化学计量比对镓酸镁尖晶石陶瓷微波介电性能的影响

摘要/Abstract

摘要： 尖晶石型微波介质陶瓷因高品质因数和可调的谐振频率温度系数在无线通信等领域应用广泛。本文通过无压烧结制备了MgO·nGa₂O₃(n=0.975、1.00、1.08和1.17)尖晶石陶瓷,采用XRD Rietveld全谱拟合研究了化学计量比对晶体结构的影响,并结合键价理论模型探究了微波介电性能与晶体结构的关系。结果表明:MgO·nGa₂O₃陶瓷相对介电常数(ε_r)的变化与晶格常数和离子极化率有关;品质因数(Q×f)受键强和阳离子有序度的共同影响,随n值增大从165 590 GHz下降至109 413 GHz;而谐振频率温度系数(τ_f)与晶体热膨胀系数相关。制备的MgO·0.975Ga₂O₃陶瓷具有优异的微波介电性能:ε_r=9.69、Q×f=165 590 GHz(频率14 GHz下)和τ_f=-7.12×10^-6/℃。

关键词: 镓酸镁尖晶石, 化学计量比, 晶体结构, 微波介质陶瓷, 介电常数, 品质因数

Abstract: Spinel-type microwave dielectric ceramics are widely applied in wireless communication due to its high quality factor and adjustable resonant frequency temperature coefficient. In this paper, MgO·nGa₂O₃ (n=0.975, 1.00, 1.08 and 1.17) spinel ceramics were prepared by pressureless sintering. The influence of stoichiometric ratio on the crystalline structure was studied by the XRD Rietveld whole pattern fitting method. The relationship between microwave dielectric properties and crystalline structure was explored through the bond valence theory model. The variation of relative dielectric constant (ε_r) of MgO·nGa₂O₃ ceramics is related to the lattice constant and ion polarizability. The quality factor (Q×f) decreases from 165 590 GHz to 109 413 GHz as n increases, which is affected by bond strength and the degree of cation order. The resonant frequency temperature coefficient (τ_f) is related to the crystal thermal expansion coefficient. The obtained MgO·0.975Ga₂O₃ ceramics possess excellent microwave dielectric properties: ε_r=9.69, Q×f=165 590 GHz (at 14 GHz) and τ_f=-7.12×10^-6/℃.

Key words: MgO·nGa₂O₃, stoichiometric ratio, crystalline structure, microwave dielectric ceramics, dielectric constant, quality factor

中图分类号:

TQ174

杨铭, 徐鹏宇, 王斌, 郑凯平, 涂兵田, 王皓. 化学计量比对镓酸镁尖晶石陶瓷微波介电性能的影响[J]. 人工晶体学报, 2022, 51(3): 508-515.

YANG Ming, XU Pengyu, WANG Bin, ZHENG Kaiping, TU Bingtian, WANG Hao. Influence of Stoichiometric Ratio on the Microwave Dielectric Properties of MgO·nGa₂O₃ Spinel Ceramics[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(3): 508-515.

参考文献

[1] 廖燕君,蒙柳方,刘秋颖,等.SrTiO₃/Mg₆Ti₅O₁₆复合陶瓷的微波介电性能研究[J].人工晶体学报,2018,47(4):734-738.
LIAO Y J, MENG L F, LIU Q Y, et al. Study on microwave dielectric properties of SrTiO₃/Mg₆Ti₅O₁₆ composite ceramics[J]. Journal of Synthetic Crystals, 2018, 47(4): 734-738(in Chinese).
[2] 宋福生,李月明,沈宗洋,等.Zn_1-xMg_xZrNb₂O₈微波介质陶瓷的结构与性能研究[J].人工晶体学报,2015,44(8):2225-2230.
SONG F S, LI Y M, SHEN Z Y, et al. Structure and properties of Zn_1-xMg_xZrNb₂O₈ microwave dielectric ceramics[J]. Journal of Synthetic Crystals, 2015, 44(8): 2225-2230(in Chinese).
[3] WU S P, XUE J J, WANG R, et al. Synthesis, characterization and microwave dielectric properties of spinel MgGa₂O₄ ceramic materials[J]. Journal of Alloys and Compounds, 2014, 585: 542-548.
[4] CAI J Z, PANG R, YU Z, et al. Preparation and luminescence properties of near infrared luminescent material Mg₂SnO₄:Cr³⁺[J]. Chinese Journal of Luminescence, 2019, 40(12): 1505-1513.
[5] 张瑶,丁士华,刘杨琼,等.Ba_1-xMg_xAl₂Si₂O₈晶体结构与微波介电性能的研究[J].无机材料学报,2017,32(1):91-95.
ZHANG Y, DING S H, LIU Y Q, et al. Crystal structure and microwave dielectric property of Ba_1-xMg_xAl₂Si₂O₈[J]. Journal of Inorganic Materials, 2017, 32(1): 91-95(in Chinese).
[6] LUO H, FANG W S, FANG L, et al. Microwave dielectric properties of novel glass-free low temperature firing ACa₂Mg₂V₃O₁₂ (A=Li, K) ceramics[J]. Ceramics International, 2016, 42(8): 10506-10510.
[7] XIANG H C, FANG L, JIANG X W, et al. A novel temperature stable microwave dielectric ceramic with garnet structure: Sr₂ NaMg₂V₃O₁₂[J]. Journal of the American Ceramic Society, 2016, 99(2): 399-401.
[8] 方亮,李威,闻望喜,等.AB₂O₄型尖晶石结构微波介质陶瓷研究进展[J].电子元件与材料,2017,36(5):1-5+11.
FANG L, LI W, WEN W X, et al. Research progress on AB₂O₄-type spinel microwave dielectric ceramics[J]. Electronic Components and Materials, 2017, 36(5): 1-5+11(in Chinese).
[9] SURENDRAN K P, BIJUMON P V, MOHANAN P, et al. (1-x)MgAl₂O₄-xTiO₂ dielectrics for microwave and millimeter wave applications[J]. Applied Physics A, 2005, 81(4): 823-826.
[10] BELOUS A, OVCHAR O, DURILIN D, et al. High-Q microwave dielectric materials based on the spinel Mg₂TiO₄[J]. Journal of the American Ceramic Society, 2006, 89(11): 3441-3445.
[11] AMIN B, KHENATA R, BOUHEMADOU A, et al. Opto-electronic response of spinels MgAl₂O₄ and MgGa₂O₄ through modified Becke-Johnson exchange potential[J]. Physica B: Condensed Matter, 2012, 407(13): 2588-2592.
[12] SURENDRAN K P, SANTHA N, MOHANAN P, et al. Temperature stable low loss ceramic dielectrics in (1-x)ZnAl₂O₄-xTiO₂ system for microwave substrate applications[J]. The European Physical Journal B, 2004, 41(3): 301-306.
[13] XUE J J, WU S P, LI J H. Synthesis, microstructure, and microwave dielectric properties of spinel ZnGa₂O₄ ceramics[J]. Journal of the American Ceramic Society, 2013, 96(8): 2481-2485.
[14] LU X C, DU Z H, QUAN B, et al. Structural dependence of the microwave dielectric properties of Cr³⁺-substituted ZnGa₂O₄ spinel ceramics: crystal distortion and vibration mode studies[J]. Journal of Materials Chemistry C, 2019, 7(27): 8261-8268.
[15] ZHENG C W, WU S Y, CHEN X M, et al. Modification of MgAl₂O₄ microwave dielectric ceramics by Zn substitution[J]. Journal of the American Ceramic Society, 2007, 90(5): 1483-1486.
[16] XU P Y, WANG H, REN L, et al. Theoretical study on composition-dependent properties of ZnO·nAl₂O₃ spinels. Part I: optical and dielectric[J]. Journal of the American Ceramic Society, 2021, 104(10): 5099-5109.
[17] TAKAHASHI S, OGAWA H, KAN A. Electronic states and cation distributions of MgAl₂O₄ and Mg_0.4Al_2.4O₄ microwave dielectric ceramics[J]. Journal of the European Ceramic Society, 2018, 38(2): 593-598.
[18] TAKAHASHI S, KAN A, OGAWA H. Microwave dielectric properties and cation distributions of Zn_1-3xAl_2+2xO₄ ceramics with defect structures[J]. Journal of the European Ceramic Society, 2017, 37(9): 3059-3064.
[19] TAKAHASHI S, KAN A, OGAWA H. Microwave dielectric properties and crystal structures of Mg_0.7Al_2.2O₄ and Mg_0.4Al_2.4O₄ ceramics with defect structures[J]. Journal of the American Ceramic Society, 2017, 100(8): 3497-3504.
[20] XU P Y, WANG H, ZHENG K P, et al. Novel transparent ZnO·3Al₂O₃ ceramics prepared by reactive hot isostatic pressing[J]. Journal of the European Ceramic Society, 2022, 42(2): 724-728.
[21] BROWN J J. Manganese-activated luminescence in the MgO-Al₂O₃-Ga₂O₃ system[J]. Journal of the Electrochemical Society, 1967, 114(3): 245.
[22] SICKAFUS K E, WILLS J M, GRIMES N W. Structure of spinel[J]. Journal of the American Ceramic Society, 2004, 82(12): 3279-3292.
[23] SULLIVAN R M. A historical view of ALON[C]//Window and Dome Technologies and Materials Ⅸ, SPIE Proceedings. Orlando, Florida, USA. SPIE, 2005.
[24] 李石峤,王斌,徐鹏宇,等.MgO·1.15Ga₂O₃陶瓷的晶体结构、振动谱及本征介电性能[J].硅酸盐学报,2021,49(9):1935-1942.
LI S Q, WANG B, XU P Y, et al. Crystalline structure, vibrational spectra and intrinsic dielectric properties of MgO·1.15Ga₂O₃ ceramic[J]. Journal of the Chinese Ceramic Society, 2021, 49(9): 1935-1942(in Chinese).
[25] TING C J, LU H Y. Defect reactions and the controlling mechanism in the sintering of magnesium aluminate spinel[J]. Journal of the American Ceramic Society, 1999, 82(4): 841-848.
[26] DONG M Z, YUE Z X, ZHUANG H, et al. Microstructure and microwave dielectric properties of TiO₂-doped Zn₂SiO₄ ceramics synthesized through the sol-gel process[J]. Journal of the American Ceramic Society, 2008, 91(12): 3981-3985.
[27] BI J X, YANG C H, WU H T. Correlation of crystal structure and microwave dielectric characteristics of temperature stable Zn_1-xMn_xZrNb₂O₈ (0.02≤x≤0.1) ceramics[J]. Ceramics International, 2017, 43(1): 92-98.
[28] SHANNON R D, ROSSMAN G R. Dielectric constant of MgAl₂O₄ spinel and the oxide additivity rule[J]. Journal of Physics and Chemistry of Solids, 1991, 52(9): 1055-1059.
[29] SHANNON R D. Dielectric polarizabilities of ions in oxides and fluorides[J]. Journal of Applied Physics, 1993, 73(1): 348-366.
[30] SURENDRAN K P, SEBASTIAN M T, MANJUSHA M V, et al. A low loss, dielectric substrate in ZnAl₂O₄-TiO₂ system for microelectronic applications[J]. Journal of Applied Physics, 2005, 98(4): 044101.
[31] WU S P, XUE J J, FAN Y X. Spinel Mg(Al, Ga)₂O₄ solid solution as high-performance microwave dielectric ceramics[J]. Journal of the American Ceramic Society, 2014, 97(11): 3555-3560.
[32] BROWN I D. Recent developments in the methods and applications of the bond valence model[J]. Chemical Reviews, 2009, 109(12): 6858-6919.
[33] LIU X, WANG H, LAVINA B, et al. Chemical composition, crystal structure, and their relationships with the intrinsic properties of spinel-type crystals based on bond valences[J]. Inorganic Chemistry, 2014, 53(12): 5986-5992.
[34] LIU X, WANG H, WANG W M, et al. Simple method for the hardness estimation of inorganic crystals by the bond valence model[J]. Inorganic Chemistry, 2016, 55(21): 11089-11095.
[35] BRESE N E, O’KEEFFE M. Bond-valence parameters for solids[J]. Acta Crystallographica Section B Structural Science, 1991, 47(2): 192-197.
[36] KAN A, MORIYAMA T, TAKAHASHI S, et al. Cation distributions and microwave dielectric properties of spinel-structured MgGa₂O₄ceramics[J]. Japanese Journal of Applied Physics, 2013, 52(9S1): 09KH01.
[37] HU M Z, GU H S, CHU X C, et al. Crystal structure and dielectric properties of (1-x)Ca_0.61Nd_0.26TiO_3+xNd(Mg_1/2Ti_1/2)O₃ complex perovskite at microwave frequencies[J]. Journal of Applied Physics, 2008, 104(12): 124104.
[38] HU M Z, FU Y, LUO C Y, et al. Microstructure and microwave dielectric properties of xCa(Al_0.5Nb_0.5)O₃+(1-x)SrTiO₃ solid solutions[J]. Journal of the American Ceramic Society, 2010, 93(10): 3354-3359.
[39] ZHANG S Y, LI H L, ZHOU S H, et al. Estimation thermal expansion coefficient from lattice energy for inorganic crystals[J]. Japanese Journal of Applied Physics, 2006, 45(11): 8801-8804.
[40] WANG G, ZHANG D N, HUANG X, et al. Crystal structure and enhanced microwave dielectric properties of Ta⁵⁺ substituted Li₃Mg₂NbO₆ ceramics[J]. Journal of the American Ceramic Society, 2020, 103(1): 214-223.
[41] WANG G, ZHANG D N, LI J, et al. Structural dependence of microwave dielectric performance of wolframite structured Mg_1-xCa_xZrNb₂O₈ ceramics: crystal structure, microstructure evolution, Raman analysis and chemical bond theory[J]. Journal of the European Ceramic Society, 2021, 41(6): 3445-3451.