Table of Content

15 March 2017, Volume 46 Issue 3

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Synthesis and Characterization of ZnGeAs2 Polycrystal

ZHONG Yi-kai;ZHAO Bei-jun;HE Zhi-yu;HUANG Wei;CHEN Bao-jun;ZHU Shi-fu;YANG Deng-hui;FENG Bo

2017, 46(3):  393-397. 

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Ternary chalcopyrite semiconductor ZnGeAs2 is a nonlinear optical material, which is expected to have important applications in laser frequency conversion.In this paper, the formation and synthesis mechanism of ZnGeAs2 polycrystal were discussed, and a method of ZnGeAs2 polycrystal synthesis was reported.High-purity (6N) Zn, Ge and As, were weighed as raw materials according to the stoichiometry with the excess of 1‰ Zn and 2‰ As.A single-phase ZnGeAs2 polycrystalline ingot was successfully synthesized, using two-temperature zone synthesis method, combining with mechanical oscillation, temperature oscillation and gradient cooling techniques.The X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS) results show that the lattice constants of the synthesized products are a=b=0.56745 nm, c=1.11580 nm, which are consistent with the standard PDF card (No.730397).The atomic ratio of the elements is Zn∶Ge∶As=1.00∶0.98∶1.95, which is close to the ideal stoichiometric ratio.The results demonstrate that the synthesized products can be used for the growth of ZnGeAs2 single crystals, and lay a good foundation for further study of nonlinear optical properties and applications on ZnGeAs2 crystals.

Effect of Annealing Temperature on the Structure and Ferromagnetic Properties of Co-doped CeO2 Diluted Magnetic Oxide Thin Films

YANG Sheng-hong;ZHANG Yue-li

2017, 46(3):  398-403. 

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Effect of annealing temperature on the structure and ferromagnetic properties was investigated for 3;Co doped CeO2 diluted magnetic oxide thin films prepared on Si(100) and quartz glass substrates by sol-gel method.The film samples were annealed at temperature of 500 ℃, 600 ℃ and 700 ℃.Then, X-ray diffraction (XRD), Raman spectroscopy, optical transmittance spectrum and superconducting quantum interference device (SQUID) were used to clarify the effect of annealing temperature on the structure and ferromagnetism of the film.The XRD and Raman spectroscopy results show a clear increasing of the crystallization degree of the film annealed under high temperature.The XRD also show that all Ce0.97Co0.03O2 thin films polycryatalline with the same structure of CeO2.The average crystallite size increases with increasing annealing temperature.Transmission spectrum studies show that all Ce0.97Co0.03O films anneal have no significant variance over absorption edge, and the optical band gap Eg decrease as increasing annealing temperature.The magnetic measurements of all films using SQUID clearly indicate the room temperature ferromagnetic behavior, and the remanent magnetization and the coercive field increase with increasing annealing temperature.The largest remanent magnetization and coercive field are obtained for the film annealed at 700 ℃.The structure of the Ce0.97Co0.03O2 film is revealed to affect their ferromagnetic properties.

Crystal Growth of Trans-stilbene by Solution Cooling Method

REN Ji-qi;CHANG Xin-an;CHEN Xue-an;XIAO Wei-qiang;ZHANG Ming-rong

2017, 46(3):  404-409. 

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The crystalline habit, solubility and metastable zone of trans-stilbene (TSB) in organic solvents had been observed and measured.TSB crystal were grown from the corresponding solutions by temperature reduction technique within 50-30 ℃, and the centimeter-size crystals obtained had high transparency.The measurements of the XRD and the UV-NIR transmission, absorption and UV fluorescence spectra of the crystal show that the alternation of the growth solvents doesn't lead any effect on the crystal structure property, the transmittance of the crystal is more than 80; in the wavelength range of 410-1000 nm, but there is absorption in the range of 200-360 nm, and a strong fluorescence emission peak appears at 386 nm by the action of exciting light of 272.8 nm on the crystal.

Preparation and Luminescent Properties of Y2O3∶Yb3+,Tm3+ Nanopowders

LUO Jun-ming;JIAO Ya-mei;DENG Li-ping;XU Ji-lin

2017, 46(3):  410-415. 

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The Y2O3∶Yb3+,Tm3+ nanopowders were prepared by chemical coprecipitation method, in which the Y2O3 was as the matrix, the Yb3+ was as the sensitizer and the Tm3+ was as the activator.The differential thermal analysis, infrared spectroscopy, X-ray diffraction, fluorescence, up-conversion luminescence and field emission scanning electron microscope were employed to characterize the nanopowders.The results show that the Tm3+ and Yb3+ can completely dissolve into the Y2O3 cubic lattice.The nanopowders exhibit uniform with the diameter of 50 nm.The fluorescence intensity and up-conversion luminescence intensity reach the maximum values at the calcination temperature of 900 ℃.The fluorescence intensity of green light (5F4/5S2→5I8) and red light (2F5/2→2F7/2) reaches maximum values at the Tm3+ concentration of 0.4;.The up-conversion luminescence intensity of blue light (1G4→3H6) and red light (1G4→3F4) reaches the maximum values at the Tm3+ concentration of 0.5;.

Surface Oxidation and Metallization of AlN Ceramics by Mo-Mn Process

CAO Chang-wei;FENG Yong-bao;QIU Tai;LIANG Tian

2017, 46(3):  416-421. 

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Metallized layer was prepared by normal Mo-Mn progress on the surface of the oxidized AlN ceramics, which were prepared by pressureless sintering method.And the Mo-Mn/Ni composite metallized layer was obtained by plating nickel on the surface of the Mo-Mn metal layer.The effects of oxidation and metallization of AlN ceramics on thermal property, mechanical property, surface phase composition and microstructure were studied.The results show that a uniform Al2O3 layer is prepared on the surface of AlN ceramics after oxidized at 1100 ℃ for 3 h.Thermal conductivity and flexural strength increase by 6.2; and 26.6;, respectively.Mo-Mn/Ni composite metallization layer is generate on the oxidized AlN sample by Mo-Mn progress and electroless plating process.The thickness of the Mo-Mn/Ni composite metallization layer prepared on the suface of AlN ceramic is about 28 μm.The diffusion layer is formed among the Al2O3 layer, Mo-Mn layer and Ni layer through the migration of elements, and the interlayer combinations are tight.The thermal diffusivity increase by 3.8; compared with the AlN ceramic substrate.

Preparation of Dental Resin Based Composites by Surface Modified Hydroxyapatite Whisker

LEI Yun;HUANG Jie;LIU Jin-kun;YAN Ting-ting;CHEN Qing-hua

2017, 46(3):  422-426. 

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HAP whiskers were prepared and surface modified via silicon Sol which formed SiO2 particles on the whisker , then the surface modified HAP whiskers were mixed into methacrylate ester to prepare resin composite.Silica modification relied on the silica sol which forms droplets of gel combined with whisker on the surfaces and forming a strong bond via heat treatment.XRD patterns, FT-IR spectroscopy and SEM were applied in order to character the micro-structure and bond nature as well as the surface phase composition.It is shown that SiO2 particles adhered on the surfaces of HAP whiskers, raising the calcination temperature significantly increased the amounts of SiO2 particles as well as the particle size.The bending strength of the resin material is increased following the raising of calcining temperature treated on modified whiskers.The resin sample prepared by the raw material of HAP whiskers calcined at 600 ℃obtained the highest bending strength, which measured 89.46 MPa.

Synthesis, Crystal Structure and Magnetic of a Copper(II) Complex with N-(4-pyridylmethyl)-L-serine

LI Yan-hong;LU Li-ping;FENG Si-si

2017, 46(3):  427-432. 

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The coordination polymer {[Cu2(L)2(Cl)2]·H2O}n(I) has been synthesized from the reaction of the amino acid reduced Schiff base HL (N-(4-pyridylmethyl)-L-serine) with CuCl2·2H2O at room temperature using diffusion method.The compound was characterized via elemental analysis, FTIR, single-crystal X-ray diffraction, powder X-ray diffraction and thermogravimetric analysis.The crystal structure consists of two crystallographically independent Cu(II).Cu1 possesses a distorted octahedral CuO2N2Cl2 geometry.Cu2 displays a slightly distorted square pyramid geometry.The L-anion via the pyridyl N atom and chloride ion bridge Cu1 and Cu2 to extend into a 2D network structure.Variable temperature magnetic studies show that complex I is ferromagnetic coupling between 300 K and 2 K.

Lithium Diffusion in Low MgO-doped Lithium Niobate Crystals at High Temperature

LI Qing-lian;SUN Jun;SHANG Ji-fang;YANG Jin-feng;ZHANG Ling;XU Jing-jun

2017, 46(3):  433-438. 

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Lithium diffusion in low MgO-doped LiNbO3 crystals was investigated under Li rich environment at high temperature.The vapor transport equilibration (VTE) method was used to prepare 1 mol; MgO-doped LiNbO3 (Mg1LN) crystals with widely varying diffusion-limited Li2O content profiles.The thermal analyzer was used to measure the Curie temperature of samples.Mg1LN polycrystalline powders with different Li2O content were prepared to fit the correlation between the Li2O content and Curie temperature.A Boltzmann-Matano mathematical method was used to solve the diffusion equation.Results show that at the temperature of 1100 ℃, the diffusivity of Li+ increases from 3.2×10-9 cm2/s ([Li2O] is 48.7mol;) to 13.0×10-9 cm2/s ([Li2O] is 49.56mol;), and the diffusivity increases nearly three times at 1145 ℃ than that at 1100 ℃.It can be concluded that increasing the diffusion temperature reasonably is an effective way to improve the efficiency for preparing stoichiometric low MgO-doped LiNbO3 crystals by VTE method.

Properties of Impurites and Defects in Crsystalline Silicon Solar Cell Based on the Dark I-V Characteristic Curves

SONG Yang;LU Xiao-dong;WANG Ze-lai;ZHAO Yang;LYU Hang;ZHANG Yu-feng

2017, 46(3):  439-444. 

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The dark I-V characteristic curve is an effective method to monitor the impurities and defects in the crystalline silicon solar cells.The influence of the properties of impurities and defects on the dark I-V characteristic curve has been systematically discussed by finite difference method, and the basic criteria for determining the type and distribution of impurities and defects in the crystalline silicon solar cells by the dark I-V characteristic curve is given, the results show that the obvious change of the dark I-V characteristic curve can be considered to be caused by the impurities and defects in the silicon solar cell under the forward bias conditions which voltage is greater than 0.75 V;the partition properties of the ideal factor of the dark I-V characteristic curve can be used as the basis of the bulk and surface impurities and defects of the crystalline silicon solar cell under the forward bias conditions which voltage is between 0.1V and 0.75 V.

Preparation, Characterization and Antibacterial Activity of Nano-Cu2O/Ag Composites

GUO Xiao-hua;MA Jian-qi;GE Hong-guang

2017, 46(3):  445-450. 

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Monodisperse Cu2O colloidal spheres were produced by a sol-gel reaction process.The sub-micrometer sized Cu2O/Ag composite spheres with core-shell structure were obtained via galvanic replacement method.The as-prepared composites were characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy.Their antibacterial activities against Bacillus subtilis (B.subtilis)and Escherichia coli (E.coli) were also studied.The results show that the average size of Ag nanoparticles (NPs) and Cu2O in the composites is about 7 nm and 150 nm, respectively.Owing to the synergistic action of Cu2O and Ag NPs, the Cu2O/Ag composites show 93; antibacterial activity against E.coli, and the antibacterial rate can reach 95; against B.subtilis.

Preparation of Structure Controlled Fluorapatite Hydroxyapatite Microsphere by Dissolution Crystallization

YUE Xue-tao;TIAN Qing-bo;FENG Li-ming;ZHANG Feng-qing;SUI Yu-wu;SUN Kang-ning

2017, 46(3):  451-456. 

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The purpose of this paper was to prepare fluorapatite microspheres with hydroxyapatite powers by simple methods.FAP microspheres were prepared by adding NaF into HAP suspension which was produced by dipped HAP powders into acetic acid-solution, and the suspension was stirred thoroughly and heated in water bath.The formation mechanism, structure and chemical constituent of the microspheres were investigated through various characterization including TEM, SEM, XRD and FT-IR.The results show that the morphology and structure of FAP microspheres could be controlled by change the pH value of acetic acid-solution.

Preparation of ZnWO4-ZnO Composite Photocatalyst and Its Photocatalytic Activity

HAO Yan-yan;ZHANG Ying;ZHAO Lin;YAN Song

2017, 46(3):  457-462. 

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A serious of ZnWO4-ZnO composite photocatalysts with various ZnWO4 concentrations were prepared by calcined mixed ZnO and WO3 powder at different temperature.The photocatalysts were characterized by X-ray diffraction, scan electron microscopy and energy dispersive X-ray spectroscopy.The photocatalytic activity of the samples was evaluated by photocatalytic degradation of Rhodamine B under UV light irradiation.The results show that the photocatalytic activity of the ZnWO4-ZnO composite catalyst is depend on the calcination temperature and the molar ratio of ZnWO4 to ZnO.The ZnWO4-ZnO composite photocatalyst with 4mol; concentration of ZnWO4 show the highest degradation rate.The high efficiency of the ZnWO4-ZnO composites is explain by the improved charge separation of the photogenerated electron-hole pairs.

Effect of Heat-treatment Temperature and Additive Content on Micro-morphology of Boron Carbide Synthesized by Microwave Sintering

ZHANG Shi-hao;FAN Bing-bing;GAO Qian-cheng;LIU Yang-fan;ZHANG Rui

2017, 46(3):  463-467. 

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Microwave sintering technique has recently attracted more and more attentions, due to its special heating such as high-efficiency, fast and energy-saving.Boron carbide (B4C) nano-powders were successfully synthesized by microwave sintering through rapid crabon-thermal reduction (RCR), with coal(C) and boric acid(H3BO3) used as raw minerals and in a 2.45 GHz microwave furnace (TE666) without any catalysts or shielding gas atmosphere.As a result, B4C crystals in different morphologies of nanosheets or particles can be obtained by microwave sintering at 1400-1800 ℃ for 5 min, when the weight ratio of coal to boric acid is 3∶1.The morphology of B4C crystals can be controlled by adjusting the relative parameters, obtaining spherical particles with diameter of 50-150 nm or boron carbide lamellar structure.Different sizes of B4C nanosheets with edge lengths form 200 to 800 nm can be obtained by changing the content of Na2CO3 additive (3wt;-9wt;), which can't be achieved by conventional resistance sintering.

Critical Transition Size of Tetragonal Zirconia Prepared with Different Stabilizers

ZHAO Zhi-long;XUE Qun-hu;ZHAO Liang;TIAN Li-ping

2017, 46(3):  468-474. 

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Nano-sized zirconia powders were prepared by sol-gel method using ZrOCl2·8H2O as the starting material, NH3·H2O and NaOH solution as precipitants.Different stabilizers were added into the precursor.Tetragonal zirconia samples with different particle sizes and tetragonal phase content were obtained after filtration, drying and calcination.The particle size and phase composition of the powders were characterized by a laser nano particle analyzer and XRD respectively.The content of tetragonal phase and grain size were calculated using Scherer formula and crystal face formula.The relationship between tetragonal phase content and particle size of zirconia powders added into different stabilizers at room temperature was analyzed.The results indicate that Nano-zirconia powder stabilized with Y2O3 is finer in particle size and more uniformity in particle size distribution.After calcine at 400-1000 ℃ for 2 h, the critical particle sizes of phase transition of nano-zirconia powder stabilize with MgO, CaO, Y2O3 are respectively 24-28 nm, 26-33.6 nm, 18-22.6 nm , based on the relationship between tetragonal phase content and cumulative distribution of particle size in nano-sized zirconia powders.

Preparation of Foaming Ceramics with Shangluo Molybdenum Tailings

ZHAO Wei;ZHANG Guo-chun;ZHOU Chun-sheng;HAN Xi

2017, 46(3):  475-479. 

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Using Shangluo molybdenum tailings as main raw materials, and adding potassium feldspar, kaolin and SiC as foaming agent, the lightweight thermal insulation foaming ceramics with high content of molybdenum tailings are prepared in this work.The order of four factors which impact the volume density of foaming ceramics is SiC content, heating rate, holding time and sintering temperature, respectively.The samples of lightweight thermal insulation foaming ceramics are sintered with heating rate of 8 ℃/min to 800 ℃, then 1 ℃/min to 1140 ℃ for 20 min.The volume density of the foaming ceramics is 0.34 g/cm3.The compressive strength is 3.2 MPa, and the average pore diameter is 1.8 mm.

Effect of CeO2 Addition on Sintering Property and Microstructure of CaTiO3 Ceramics

2017, 46(3):  480-485. 

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CaTiO3 ceramics were prepared via solid-state reaction method using CaO and TiO2 as main raw materials.The effects of CeO2 additive on the sintering property and microstructure of CeO2-doping ceramic were mainly studied.The crystalline phase composition, microstructure and sintering characteristics of the specimens were investigated by XRD, SEM, EDS and so on.The lattice parameters and cell volume of CaTiO3 were determined and calculated by X'pert High score Plus software.The results show that the lattice parameters and lattice volume of Ce-doping CaTiO3 are affected by the substitution of Ce3+ for Ca2+ and Ce4+ for Ti4+ in the structure of CaTiO3.With increasing the additive, the lattice parameters and lattice volume increase first and then decrease.Structure defect of solid solution accelerated diffusion of ion and promoted synthesis rate of CaTiO3, resulting in the increase of grain size.The shape of crystal grain change from steps' morphology to regular polygons with excessive addition of CeO2, while the average crystal size decrease.Thermal defects caused by higher sintering temperature also promote the solid reaction and sintering of synthetic CaTiO3.

Effect of Copper Evaporation Temperature on the Performance of Cu2ZnSnSe4 Thin Film Solar Cells Prepared by Co-evaporation Process

2017, 46(3):  486-489. 

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To know well the effect of Cu concentration on the performance of of Cu2ZnSnSe4 (CZTSe) thin film solar cells.CZTSe thin film solar cells prepared at different Cu evaporation temperature was investigated.The results indicate that the low TCu(1400 ℃) cause additional reflections of secondary phase SnSe and the films are N-type conduction.The quality of crystallization of CZTSe films is improved with increasing TCu.But the secondary phase of CuxSey is observed for CZTSe films deposited at TCu of 1500 ℃.Both secondary phase of SnSe and CuxSey could cause devices electrically inactive.The best solar cell with an efficiency of 2.63; is obtained at medium TCu of 1450 ℃ (active area 0.34 cm2).

Catalytic Performance of Fe-doped Mn/TiO2 Catalysts for Low-temperature Denitration

LIU Na;HE Feng;XIE Jun-lin;HU Hua;LI Feng-xiang;FANG De

2017, 46(3):  490-494. 

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The Fe-Mn/TiO2 catalysts for low-temperature denitration with different dosages of Fe were prepared by oxidation precipitation-impregnation method.The catalytic activity was discussed at 80-180 ℃.The physical and chemical properties were characterized using XRD, BET, TG, H2-TPR, NH3-TPD.The results show that there is no change in main crystal phase of Mn/TiO2 along with the addition of Fe and the main crystal phase is still anatase while FeOx and MnOx highly dispersed on the carrier surface with amorphous structure.According to the results analysis, it turns out that the micro-structure and surface acidity could be improved effectively with the addition of Fe.Catalyst dispersion, specific surface area and the amount of Bronsted acid sites are increase significantly, accordingly leading to the improvement in catalytic activity.Specifically, the NO conversion of 0.10 Fe-Mn/TiO2 could be up to 90; at 120 ℃.

Preparation of Alpha-alumina Platelets by Sodium Sulfate Molten Salt

WANG Xue-zhu;WU Feng;ZHANG Ming-wang;SUN Na-na;FANG Hui;XUE Zong-wei;LI Xin-wei

2017, 46(3):  495-500. 

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The alpha-alumina platelets were prepared in sodium sulphate molten salt by dry method mixing molten salt and different source γ-Al2O3 respectively.The γ-Al2O3 was prepared with aluminum sulfate octadecahydrate and aluminum hydroxide respectively.The results indicate that the alumina platelets cannot be prepared in sodium sulphate molten salt with aluminum hydroxide as the source of γ-Al2O3.The decomposed aluminum hydroxide remaine pseudomorph of the spherical polyhedron.A small amount of alumina platelet is grown and inserted in the spherical polyhedron through dissolution-precipitation due to molten salt could only dissolved alumina in the spherical polyhedron surface.The dispersed alumina platelets could be obtained in sodium sulphate molten salt with aluminum sulfate octadecahydrate as the source of γ-Al2O3.The well dispersed γ-Al2O3, decomposed from aluminum sulfate octadecahydrate, completely dissolve in molten salt, then alumina platelets precipitated out in molten salt when the molar ratio of γ-Al2O3∶Na2SO4 is 1∶4.

Light Absorption Enhancement of Organic Solar Cells Incorporated by Nanospheres and Core/Shell Nanospheres

CHEN Ming;REN Jing-kun;ZHANG Ye

2017, 46(3):  501-506. 

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The paper investigates the light trapping capability enhancement of the active layer incorporating silica nanosphere, silver nanosphere, silica/silver core/shell-nanospheres, and silver /silica core/shell-nanospheres respectively in the patterned organic solar cells.The results show that compared with the structurally identical planar control cell, the integrated light absorption efficiency in the active layer incorporating silica nanospheres is enhanced by 9.95;, the integrated light absorption efficiency of the active layer incorporating silver nanospheres is enhanced by 11.0;.In addition, the study on organic solar cells incorporating the core/shell nanospheres reveals that the efficiency including silica/silver core/shell-nanosphere increases with the increase of silver coating thickness increase.Moreover, as the metal coating thickness is 16 nm, this light absorption enhancement performance approximates the optimal organic solar cell with silica nanospheres and both absorption spectra exhibit nearly close.The efficiency brought by silver/silica core/shell-nanospheres decreases by the decrease of silica coating thickness.Compared with the silver nanospheres, both exhibit the approximate enhancement performance and approximate absorption spectra as coating thickness is fixed 1 nm.Through the study of light absorption enhancement performance of the active layer incorporating dielectric nanospheres, metal nanospheres, and core/shell-nanospheres, this paper provides the guideline for choose nanospheres and core/shell structures incorporated in the active layer into enhancing the light absorption.

Effect of Al2O3 on Sintering and Thermal Shock Resistance of MgO Ceramic

2017, 46(3):  507-513. 

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Nano-magnesia powder adhered with alumina precursor was prepared with nano-magnesia, aluminum sulfate and ammonium hydroxide by using co-precipitation method.The sintering properties at room temperature and thermal shock resistance of sintering specimens were investigated.Phase composition and the microstructure of specimens were studied by XRD and SEM methods.The effect of alumina precursor that served as sintering aid on sintering and thermal shock resistance of magnesia ceramic was studied.The results suggest that the specimens after alumina added formed magnesium aluminate spinel that increased the sintering properties, maximum bulk density is 3.48 g/cm3.There are amounts of micro-cracks and conglutination areas in the microstructure that are contributed to the thermal shock resistance to some degree.

Effect of V2O5 Doping on the Structure and Properties of 0.6SrTiO3-0.4LaAlO3 Microwave Dielectric Ceramics

HUANG Chun-e;LU Xiao-rong;LU Min-yao;HUAN Yuan

2017, 46(3):  514-518. 

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The changing relationship between additive amount of V2O5 and the sintered properties, dielectric properties of 6ST-4LA microwave dielectric ceramics which prepared by conventional solid-state route were investigated.The results show that small addition of V2O5 does not change the crystal phase of 6ST-4LA ceramics, the main phase of samples is SrTiO3-based solid solution.Moderate addition of V2O5 could not only dramatically lower the sintering temperature which dropped to 1450 ℃, but also increase the dielectric constant and the Quality factor(Q·f), and adjust the τf.The second phase SrVO3 appeared and increased gradually with increasing the content of V2O5.The 0.10wt; V2O5-doped 6ST-4LA ceramics sintered at 1450 ℃ have the optimal integrated microwave dielectric properties: εr=46.46 , Q·f=59219 GHz, τf=3×10-6 /℃.

Effect of Annealing Temperature on Properties of Mixed-Organic-Cation Perovskite Solar Cells

LIU Yao;ZHANG Fan;NIU Fang-fang;LIAN Jia-rong;SONG Jun;ZENG Peng-ju

2017, 46(3):  519-525. 

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It is an effective way to improve the photoelectric conversion efficiency of perovskite solar cells by cutting down the band gap of perovskite and broadening the range of optical absorption.In this paper, formamidine triiodoplumbite (HC(NH2)2PbI3 or FAPbI3) precursor solution mixed with a certain proportion of methyl ammonium iodide (CH3NH3I or MAI) and the annealing temperature of perovskite thin film is reduced from 150 ℃ to 100 ℃.The surface morphology and crystallinity of the films can not only effectively improve, but also get more than methyl ammonium triiodoplumbite (CH3NH3PbI3 or MAPbI3) narrow gap the film.The efficiency of perovskite photovoltaic cells is 14.8;.

Microwave Sintering of (Mg0.7Zn0.3)TiO3-Ca0.61La0.26TiO3 Dielectric Ceramics

ZHAO Li;HU Yu-ye;LI Dan;LIU Qiu-yan;SHEN Chun-ying

2017, 46(3):  526-530. 

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0.85(Mg0.7Zn0.3)TiO3-0.15(Ca0.61La0.26)TiO3 ((Mg0.7Zn0.3)TiO3-Ca0.61La0.26TiO3) system ceramics were prepared by microwave sintering.The effects of microwave sintering process on the sintering behaviour, microstructure, phase composition and microwave dielectric properties of ceramics were investigated.The results show that (Mg0.7Zn0.3)TiO3-Ca0.61La0.26TiO3 ceramics exhibited mixed phases of (Mg0.7Zn0.3)TiO3 and Ca0.61La0.26TiO3 as the main phase associated with minor phases of (Mg0.7Zn0.3)Ti2O5.When heating rate is 15 ℃/min, the (Mg0.7Zn0.3)TiO3-Ca0.61La0.26TiO3 ceramics exhibit excellent microwave dielectric properties:εr=27.01,Q·f=103500 GHz,τf=+2 ppm/℃ sintered at 1275 ℃ for 20 min.

Structure Transformation of Nano-rich Cu Phase Precipitates from 9R to fcc in Low Carbon Ferrite Steel

XIE Hui;WANG Wei

2017, 46(3):  531-535. 

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Low carbon ferritic steel samples were heat treated at 880 ℃ for 0.5 h and then water quenched,tempered at 660 ℃ for 10 h,then isothermal aged at 400 ℃ for 11000 h.The characteristics and relations of different crystal structure of nano-rich Cu phase precipitated in low carbon ferrite steel were analyzed by using high resolution transmission electron microscope (HRTEM) and energy dispersive spectroscopy (EDS).The short rod of monoclinic structure of 9R nano Cu-rich phase with mutualling twin structure were observed, which the long axis is about 9.5 nm, the short axis is about 6.6 nm.It is indicate that the early precipitation of Cu is preferentially transformed into the monoclinic structure of 9R with twin relationship, At the same time, it is observed that the fcc twin structure of Cu, as well as the fcc non-twin structure of Cu with Moire fringe, It is showed that the 9R structure not only retreat into the fcc non-twin structure, also can be directly transformed into fcc structure with twin relationship.

Theoretical Model and Experimental Study on Cutting Temperature of Brittle Materials

HE Pei;MA Lian-jie;GUO Ya-peng;DENG Hang;WANG Hua;BI Chang-bo;LI Qi;WAN Xue-wen

2017, 46(3):  536-540. 

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By developing single fracture to Continuous fracture, the times of fracture was counted using k1 the ratio of the area of surface morphology to projected area.The theoretical model of cutting temperature for brittle materials was built based on the conservation of energy of micro-fracture mechanism of cutting Brittle Materials.The theoretical model was verified through turning fluorophlogopite ceramics with carbide tool, and turning experiment is carried out.The results indicate that by using the theoretical model of cutting temperature for brittle materials, variation trend of cutting temperature drived by machining conditions is predictable within limits.

Silver Recovery Experiment by Flotation from Ammonia Leaching Slag Based on RSM

ZHAO Min-jie;FANG Jian-jun;ZHANG Tie-min;ZHANG Lin

2017, 46(3):  541-549. 

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In order to effectively recovery silver metal by flotation from copper oxide ammonia leaching residue, a 4 factors 5 level CCD response surface design was chosed.The model was established by dosage of sodium sulphide, composite collector, composite inhibitors and activators were studied as independent variables, silver flotation concentrate grade and recovery were as response.Response surface analysis results showed that activator dosage were the most significant influence on silver concentrate grade and recovery, the interaction between combination the collector and composite inhibitors dosage is the most important interaction of silver concentrate grade, and the dosage of sodium sulphide and ethylenediamine phosphate dosage is the most significant of recovery.Response surface method to optimize the result is: the dosage of sodium sulphide is 930.04 g/t, the composite inhibitor dosage 301.85g, collector dosage with 416.63 g/t and Ethylenediamine phosphate dosage is 105.90 g/t.in this condition, the maximum available silver concentrate recovery rate is 87.66;, and the corresponding grade of 877.042 g/t.Finally, according to the test, on the basis of optimization results on three roughing an scavenging twice selected closed-circuit test, test results are compared to before optimization test, recovery rate raise almost two percent point, the results show that response surface method optimization is achieved with a good results.

Investigation on Few-layer MoS2Treated by Soft Hydrogen Plasma

ZHANG Xue-cheng;XIAO Shao-qing;NAN Hai-yan;ZHANG Xiu-mei;YAN Da-wei;GU Xiao-feng

2017, 46(3):  550-554. 

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As a two-dimensional transition-metal dichalcogenide (TMDC), few-layer molybdenum disulfide (MoS2) possesses excellent optical and electrical properties and thus shows a great prospect in the field of optoelectronic functional devices.In this work, mechanically exfoliated few-layer MoS2 flakes were treated by a novel soft hydrogen plasma followed by post annealing and the resultant variations in both optical and electrical properties were systematically investigated.It has been demonstrated that hydrogen atoms may penetrate into MoS2 lattices with the help of soft hydrogen plasma and consequently change pristine lattice structure as well as lattice vibration, leading to fluorescence quenching and at the same time making n-type few-layer MoS2 become intrinsic or p-type doping.Post annealing after soft hydrogen plasma treatment may induce the bonding of a very few MoS2 molecules with hydrogen atoms, giving rise to the bule shift of optical band gap.

Electrical and Magnetic Properties of Co-doped ZnO

WANG Yue;ZHANG Jing-hui;LI Xue

2017, 46(3):  555-561. 

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Electrical and magnetic properties of Co doping ZnO prepared by simple hydrothermal method were studied.To determine the structure, morphological and properties of sample, some investigation measurements were used, such as XRD, SEM and so on.The XRD results show that Co ions incorporates into the ZnO lattice successfully with 2+ valence state, without formatting any detectable secondary phase and the substitution of Co2+ for Zn2+ does not change the original wurtzite structure of zinc oxide.For Co doped ZnO, the length and diameter was found to decrease, the reason is Co ion radius was smaller than the ironic radius of Zn.Compared with the sample unannealed, the lattice size after annealing of the sample is reduced, the crystallinity becomes better, it is reason for that anneal reduced lattice internal defects, and anneal temperature is more beneficial to the growth of crystal.The electrical transport properties and magnetoresistance (MR) effect results indicated that unannealed sample resistance is greater than annealed sample in zero magnetic field.Applied magnetic field on the sample has crucial effect on the carrier concentration and Hall mobility.All samples showed positive MR effect, which is mainly due to electron and photon localization results of band splitting the combined action.Because of the influence of internal lattice defects, unannealed sample has no sustained increase in the range of magnetic field, and the value is smaller.The reason is that annealing made lattice internal defects decreased and the water molecules conductive effect weakened, resulting in a positive magnetoresistance effect more obvious but the value is decrease.

Ferrous Chloride-Catalyzed Synthesis of Boron Carbonitride Nanotube

CAO Li-hua;CHEN Yong-jun;LI Jian-bao;LUO Li-jie;XU Zhi-chao;ZHANG Chao

2017, 46(3):  562-565. 

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An effective solid-state reaction method is reported for synthesizing boron carbonitride nanotubes (BCNNTs) with bamboo-like structure in large scale by using amorphous boron powder and ferric chloride (FeCl2) catalyst in absolute ethyl alcohol and ammonia atmosphere at elevated temperatures.The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS).The results reveal that large quantity of BCN nanotubes was synthesized and the diameter of the nanotubes ranged from 60 to 90 nm.The nanotubes are composed of elements of B, C and N, and the calculated atomic ratio of B, C and N is 9.77∶1∶8.65.The growth mechanism of BCNNTs is governed by vapor-liquid-solid (VLS) model.Moreover, the influence of reaction temperature on nanotubes was discussed.

Synthesis,Characterization and Photocatalytic Property of g-C3N4/CuO Composite

HU Yu-hong;WU Wen-wei

2017, 46(3):  566-572. 

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Graphitic carbon nitride (g-C3N4) was prepared by the thermal condensation of melamine.Then, A g-C3N4/CuO nano composite materials were prepared using Cu(NO3)2 and g-C3N4 as raw material under hydrothermal method in present of amount of ammonia with deionized water and anhydrous ethanol as solvent.The obtained photocatalyst was characterized by field emission scanning electron microscope (FE-SEM), photoelectron spectrometer (XPS) and uv-vis diffuse reflection (UV-Vis-DRS) and fluorescence spectroscopy (PL).According to the XRD, SEM and XPS test result, micro spherical CuO and g-C3N4 closely together;the UV and PL spectra show that the combination of CuO and g-C3N4 composite can expand the scope of visible light absorption and slows down the compound rate of electrons and holes.The degradation of methyl orange (MO) aqueous solution was used to evaluate the photocatalytic activity of 70-g-C3N4/CuO under visible light irradiation.The results show that in the absence of hydrogen peroxide (H2O2) system, the degradation rate of MO remains 85; after 4 h of light reaction,but the existence of H2O2 system, the photodecomposition rate of MO reached 96; after 1 h light reaction.Through laboratory experiments on the trapping free radicals, hydroxyl free radical and hole played an important role in the process of degradation of MO.After four times of circulation, the basic for the degradation of MO rate still reached 90;.Thus the g-C3N4/CuO material had good photocatalytic and stability.