Yttrium iron garnet （Y₃Fe₅O₁₂， YIG） has emerged as a highly promising functional material for next-generation optical isolators， magneto-optical switches， and integrated photonic devices， owing to its excellent optical transparency， strong Faraday rotation， low optical absorption loss， and high Curie temperature in the near- to mid-infrared spectral region. The rapid advancement of 5G/6G optical communications， fiber-optic gyroscopes， and quantum computing imposes increasingly stringent demands for high-performance， low-power magneto-optical devices， which in turn require YIG single crystals to combine a large magneto-optical response with low insertion loss and robust temperature stability. However， the incongruent melting behavior of YIG precludes the growth of high-quality single crystals by conventional Czochralski pulling， making the flux method the critical technological route for YIG crystal fabrication. This review provides a systematic overview of the evolution of flux-based growth techniques for YIG single crystals， with emphasis on the selective occupation mechanisms at the dodecahedral c-site and the associated charge-compensation principles of Bi³⁺ and representative rare-earth ions such as Tb³⁺， Ce³⁺， Gd³⁺， and Dy³⁺. From the perspective of the microscopic origins of the magneto-optical effect， the incorporation of these ions enhances the Faraday rotation predominantly by strengthening spin-orbit coupling， introducing new 4f-5d transition channels， or modifying the super-exchange interactions among the Fe³⁺ sublattices. Building on these fundamentals， this review further discusses the strategies for tailoring the magneto-optical performance in the near- to mid-infrared region and for optimizing temperature stability through ion doping. Current technical challenges， including doping homogeneity， crystal defect control， and broadband magneto-optical response， are analyzed， and future directions toward integrated-photonics-oriented magneto-optical single crystals are outlined.

Magneto-optical crystals enable unidirectional laser transmission and are widely used in nonreciprocal optical devices， including optical isolators， optical switches， playing an irreplaceable role in optical communications and high-power lasers. At present， conventional magneto-optical materials such as TGG， CeF₃， and YIG have been extensively applied in the ultraviolet， visible， and near-infrared spectral ranges. However， rather limited types of magneto-optical materials fulfill the increasing potential demands for the mid-infrared and even Terahertz ranges. Recently， hexagonal non-collinear antiferromagnets Mn₃Sn， featuring unique kagome structure and topological band， have been continuously reported in journals such as Nature. Despite its extremely small net magnetic moments， Mn₃Sn exhibits giant magneto-optical Kerr effects and anomalous Hall effects， showing great potential for mid-infrared and terahertz applications. This paper systematically reviews the recent research progress on Mn₃Sn crystals， including their magneto-optical properties， relevant modulation mechanisms， and crystal growth， aiming to provide valuable references for the design of novel magneto-optical materials.

Terbium scandium aluminum garnet （Tb₃Sc₂Al₃O₁₂， TSAG） crystal is a novel magneto-optic crystal with outstanding magneto-optical properties， which holds great promise for wide applications in high-power lasers. However， the high stress and susceptibility of TSAG crystal to cracking restrict the processing and practical utilization of corresponding optical components. To improve the crystal quality， this paper focused on the high stress problem in TSAG crystal and systematically investigated the composition distribution along the crystal growth direction and radial direction. By optimizing the crystal growth process， the composition uniformity of TSAG crystal was effectively enhanced， and ?45 mm×100 mm low-stress TSAG crystal was successfully grown. The fabricated TSAG crystal component exhibits an absorption loss coefficient of 0.19%/cm， and the developed isolator with a 3 mm clear aperture achieves a minimum isolation of 36.19 dB. The magneto-optical properties of TSAG crystals in different directions are further studied in detail. The crystal in the ［100］ direction possesses the maximum Verdet constant （51.38 rad·m^-1·T^-1）， which is beneficial for the miniaturization of isolators. The research results demonstrate that the successful development of low-stress TSAG crystal is expected to realize the application of TSAG crystal in high-power laser system.

In this paper， KDy（WO₄）₂（KDW） crystal with a size of 40 mm × 40 mm × 15 mm was successfully grown by top-seeded solution growth （TSSG） method. The crystal structural， optical quality， thermal properties， laser induced damage threshold and magneto-optical properties of KDW crystal were comprehensively studied. The rocking curve shows that the full width at half-maximum of KDW （020） wafer is 0.071 2°， indicating that the crystal has good crystal quality. The transmittance curve shows that the KDW （020） wafer has a high transmittance in the visible-near infrared band. The results of single crystal X-ray diffraction （SCXRD） refinement show that KDW crystal belongs to monoclinic I2/a space group， and ［DyO₈］， ［WO₆］ and ［KO₁₀］ groups constitute the crystal skeleton. The ［WO₆］-related vibration mode in Raman spectra matches the monoclinic KRe（WO₄）₂ system.Thermal tests indicate that the thermal conductivity， thermal diffusion coefficient and specific heat capacity of KDW crystal at 298 K are 3.792 W/（m·K）， 1.692 mm²/s and 0.307 J/（g·K）， respectively. The laser induced damage threshold of KDW （020） wafer is 745.1 MW/cm² at 1 064 nm and 10 ns. Based on the extinction method， the Verdet constants of KDW crystal at 405， 532 and 635 nm are -208.30， -82.17 and -54.01 rad/（m·T）， respectively， and the corresponding magneto-optical figure of merit （FOM） are 768.21， 615.77 and 412.52（°）/T， respectively. This study shows that KDW crystal has excellent thermal/damage resistant properties and good visible Faraday rotation ability， and is a competitive magneto-optical crystal in visible-near infrared band.

Yttrium iron garnet （Y₃Fe₅O₁₂， YIG） crystals possess exceptional magneto-optical properties， rendering pivotal for optical communication and photonic integration. Herein， YIG single crystals were grown via the optical floating zone method， and the influence of growth atmosphere on optical quality of YIG single crystal was systematically investigated. The results show that phase-pure garnet structures are successfully obtained under both air and different oxygen partial pressure atmospheres. Crucially， crystals grown under pure O₂ atmosphere exhibit superior transmittance performance in the infrared band， and its transmittance is close to the theoretical value （~75%）. This is primarily due to the higher oxygen partial pressure during the growth process， which effectively inhibits the valence change of Fe³⁺. Fe 2p X-ray photoelectron spectroscopy analysis further reveals that the relative content of Fe²⁺ is as high as 62% （mole fraction） in grown crystals under air atmosphere， but the relative content of Fe²⁺ is reduced to 9% （mole fraction） in grown crystals under pure O₂ atmosphere， which directly confirms the effective inhibition of oxygen partial pressure on the valence change of Fe³⁺ from the chemical state level， thus facilitating preparation of high-quality magneto-optical crystals. The magneto-optical performance test at 1 386 nm further confirms that the prepared YIG crystal has good magneto-optical modulation performance， and its Faraday rotation angle can reach 225 （°）/cm. This study provides a feasible path for the preparation of high-quality iron-based garnet crystals， which is of great significance for promoting the development of corresponding magneto-optical crystal functional devices.

Mid-infrared band covers two important atmospheric windows and is also the absorption fingerprint area of numerous gas molecules， making it highly valuable in diverse applications， including gas detection， environmental monitoring， industrial control， medical diagnostics， infrared countermeasures， etc. Mid-infrared interband cascade lasers （ICLs） are a class of semiconductor lasers operating in the mid-infrared band. They have the advantages of low power consumption and high efficiency. They are suitable for various application scenarios such as portable gas detection， and have gradually become competitive mid-infrared light sources. Currently， the global ICLs market is predominantly controlled by foreign corporations， while the domestic ICLs industry is still in its early stage. Therefore， it is of great significance for China to promote the development of ICLs by clarifying the market application prospect， industrial development path and technology application direction. This paper outlines the major application scenarios of ICLs， reviews the development history of ICLs， and research progress of GaSb-based， InAs-based ICLs， and ICLs heterogeneous integration in recent years is reviewed in detail. On this basis， the market prospects and challenges are analyzed， and the development of ICLs in China is prospected.

This paper reviews various methods for growing single crystals of gallium oxide （β-Ga₂O₃）， including flux method， verneuil technique， vapor phase method， Czochralski method， floating zone growth， edge-defined film-fed growth， vertical Bridgman method， casting method， oxide crystal growth from cold crucible， and drop-fed growth. It also summarizes the impact of key parameters such as doping， crystal growth processes， and heat treatment on crystal quality. By detailing the core technical parameters of each process step， the study delineates the optimal operating parameters for different crystal growth techniques. The paper compares the characteristics of various methods across multiple dimensions including achievable maximum dimensions， crystal quality， doping compatibility， crucible dependence， atmosphere control complexity and industrial scalability， and identifies the primary challenges currently facing gallium oxide single crystal technology while proposing key directions for its advancement. Furthermore， based on global industry insights， practical recommendations are provided to optimize gallium oxide crystal growth processes and enhance semiconductor material performance， aiming to facilitate large-scale production and application of gallium oxide semiconductors and drive breakthroughs in critical products such as high-power power electronic devices and deep-ultraviolet detection devices.

As the core supporting material in low-voltage switches， the performance of Ag-based electrical contacts directly influences the safety and reliability of power system operations. The application of traditional Ag/CdO is limited due to the toxicity of Cd， while existing non-toxic alternatives suffer from significant deficiencies in both microstructure and performance. MAX phase， along with their two-dimensional derivatives， MXene， combine the advantages of both metals and ceramics， showcasing distinctive characteristics in processing， electrical and thermal conductivity， and arc erosion resistance. They are therefore promising candidates as environmentally friendly reinforcement phases for Ag-based contacts. This review firstly provides a comprehensive overview of the types， development， and advantages and limitations of traditional Ag-based electrical contact materials. It further summarizes recent research advancements in the fabrication processes， composition selection， microstructural regulation， and performance optimization of Ag/MAX/MXene composites. Special emphasis is placed on the arc erosion resistance and the underlying mechanisms of Ag/MAX/MXene composites. Finally， based on the evaluation of the application potential of this composite system in electrical contacts， the current challenges and future development directions are discussed.

Owing to the coexistence of multiple order parameters and their underlying coupling effects， rare-earth orthoferrites have emerged as a focal point of research in condensed matter physics and materials science. This kind of material demonstrates significant potential for application in the next-generation electronic devices based on charge and spin degrees of freedom. As a famous member of strongly correlated system， DyFeO₃ usually crystallizes in an orthorhombic symmetry perovskite structure and displays complex spin interactions， multiple magnetic phase transitions， prominent magnetoelectric coupling effects， which are beneficial to spintronics and magnetoelectric functional devices. This review systematically summarizes various synthesis methods for DyFeO₃ reported in recent literature. It specifically examines the influence of diverse synthesis processes on the crystal structure， grain size， surface morphology， and macroscopic magnetic behavior of DyFeO₃. This work aims to navigate future research and facilitate practical applications within the DyFeO₃ system and other related rare-earth orthoferrites.

Monocrystalline silicon components serve as core parts of semiconductor equipment and are widely used in various high-temperature manufacturing processes of integrated circuits. Oxygen content dominates their performance and service life. With distinct control standards for different application scenarios， precise oxygen control is critical to industrial development. This paper investigates the influence of thermal shield position on the argon flow field， melt flow field and temperature field， and further reveals the internal mechanism of the synergistic effect between the melt flow field and temperature field on the dissolution capacity， migration flux and migration path of oxygen impurities. The results show that reducing the spacing between the thermal shield and the crystal can increase the argon flow velocity near the triple-phase point， enhance crystal heat dissipation， stabilize the growth interface and improve the removal efficiency of oxygen impurities. Meanwhile， it homogenizes the melt temperature field， inhibits quartz crucible dissolution， optimizes melt turbulent viscosity， and weakens the transport and migration of oxygen impurities in the melt. In addition， compact small eddies form on the melt surface， altering the migration path of oxygen impurities. Under the combined effect of melt flow field and temperature field， the maximum radial oxygen content of the crystal decreases by 0.275×10¹⁷ atoms/cm³， and the average value decreases by 0.206×10¹⁷ atoms/cm³.

BaTiO₃ ferroelectric nanofilms demonstrate intricate domain structures and distinct nonlinear electromechanical behaviors as a result of the constraints imposed by diverse substrates. This work utilized a phase field model grounded in the framework of continuum thermodynamics to investigated the novel characteristics imparted to ferroelectric polycrystalline nanofilm systems by the rapid polarization reversal process under different tensile and compressive strain conditions. In contrast to existing studies focusing on single-crystal epitaxial films， this paper comprehensively examined factors including grain boundary effects and grain orientation. It further simulated the impact of in-plane strain on the microstructural domain structure and electromechanical characteristics of ferroelectric polycrystalline nanofilms， considering two distinct grain sizes， 60 and 10 nm. The results indicate that for a grain size of 60 nm， both the coercive field and remnant polarization decrease monotonically， suggesting that increased compressive strain effectively enhances the ferroelectric properties of the nanofilm. Conversely， at a grain size of 10 nm， excessive compressive strain results in a sudden reduction in both remnant polarization and coercive field. Furthermore， in contrast to single-crystal films， due to the existence of grain boundaries in polycrystalline films， the domain structures （90° domains， 180° domains and vortex domain structures） of the films under different tensile and compressive strains show diversity， even if the polycrystalline films produce a variety of complex electromechanical characteristics. This study explores the micro-mechanisms of ferroelectric materials by examining their internal microstructure， with the aim of facilitating the application and regulation of the macroscopic properties of ferroelectric nanofilms. The findings provide theoretical guidance for the design of high-performance ferroelectric nanofilms microelectronic devices.

In this paper， Na₂Ca_1-x SiO₄∶xTb³⁺（x=0~0.08） and Na₂Ca_0.95SiO₄∶0.05Tb³⁺/yK⁺（y=0.03~0.07） series of green phosphors were synthesized via the high-temperature solid-state reaction method. The effects of Tb³⁺ single doping and Tb³⁺/K⁺ co-doping on the phase structure， micro-morphology， optical absorption， luminescence properties， chromaticity coordinates， and thermal stability of the samples were systematically investigated. The results demonstrate that doping does not alter the cubic crystal phase structure of the Na₂CaSiO₄ matrix， which exhibit high crystallinity. Tb³⁺ effectively occupy Ca²⁺ lattice sites and reduce the band gap of the matrix. The micro-morphology of the samples is irregular with evident agglomeration. Under excitation at 376 nm， the Na₂Ca_1-x SiO₄∶xTb³⁺ phosphor exhibits the strongest characteristic emission of Tb³⁺ corresponding to the ⁵D₄→⁷F₅ transition at 544 nm， and the optimal doping molar concentration is x=0.05. For the Na₂Ca_0.95SiO₄∶0.05Tb³⁺/yK⁺ （y=0.03~0.07） phosphors， the optimal doping molar concentration of K⁺ is y=0.05. The luminescent intensity of the optimized composition Na₂Ca_0.95SiO₄∶0.05Tb³⁺/0.05K⁺ is approximately 2.3 times that of Na₂Ca_0.95SiO₄∶0.05Tb³⁺. It possesses a fluorescence lifetime of 3.006 ms， a band gap of 5.03 eV， and CIE chromaticity coordinates of （0.255， 0.551）. At 473 K， its luminescent intensity still maintains 92.4% of that at room temperature （298 K）， indicating excellent thermal stability. This phosphor is a promising green-emitting material with potential applications in white light-emitting diodes （W-LEDs）.

Addressing the urgent demand for high color rendering index and low color temperature single-phase phosphor for near-ultraviolet-excited white light emitting diode （WLED）， this study proposed a novel color-tunable phosphor system based on MgY₂Si₃O₁₀ host co-doped with Bi³⁺and Eu³⁺. A series of MgY₂Si₃O₁₀∶0.02Bi³⁺， mEu³⁺ （m=0~0.22） samples were successfully synthesized via the high-temperature solid-state method. Their phase structure and luminescence properties were systematically characterized. The results indicate that Bi³⁺ occupies two distinct crystallographic sites in the host lattice， exhibiting a dual-peak broad-band emission under 344 nm excitation， while Eu³⁺ displays characteristic red emission. Through spectral overlap analysis and fluorescence lifetime test， it is confirmed that there is efficient energy transfer （ET） from Bi³⁺ to Eu³⁺， with its efficiency increasing with Eu³⁺ doping concentration and reaching a maximum of approximately 65%. The critical energy transfer distance （R_C） is calculated to be about 13.2 ? based on the concentration quenching model and the primary ET mechanism is electric dipole-electric quadrupole （d-q） interaction. By adjusting the Eu³⁺ doping concentration， continuous tuning of the emission color is successfully achieved， ranging from blue through white to red. The white emission exhibits chromaticity coordinates of （0.333，0.306）， a correlated color temperature （CCT） of 5 419 K， a general color rendering index （R_a） of approximately 85.6， as well as good thermal stability. This study provides systematic experimental and theoretical foundations for the development of high-performance， color-tunable phosphor materials for WLED applications.

To overcome the bottlenecks of narrow photoresponse range and the thermodynamic limitations for photocatalytic water splitting in LaTiO₃， first-principles calculations were performed to compare the modulation mechanisms of Co， Fe， and Ni single-doping. The results show that all three doped systems exhibit negative formation energies， with Ni doping yielding the lowest value （-1.14 eV）. Phonon spectra display no imaginary frequencies， confirming the kinetic stability of all systems. The band gap of pristine LaTiO₃ is 2.299 eV， which decreases to 1.674 （indirect band gap）， 1.405， and 0.928 eV for Co， Fe， and Ni doping， respectively. Notably， the band gaps for Fe and Ni doping are too narrow to satisfy the thermodynamic requirement for overall water splitting （≥1.23 eV）. -COHP and Bader charge analyses confirm the enhanced M—O covalency after doping， with the net bonding strength from high to low following the order of Co， Fe， and Ni doping， while the charge transfer strength from high to low follows the order of Ni， Co， and Fe doping， with Ni doping exhibiting the largest charge transfer （electron loss of 1.15 e）. Co doping shifts the absorption edge to 520 nm， achieving a peak visible-light absorption coefficient of 2.0×10⁵ cm^-1， and increases the work function to 3.05 eV， which is attributed to the reconstruction of the electronic density of states near the Fermi level. Based on the comprehensive evaluation of band gap， optical absorption， and charge carrier separation performance， Co doping is identified as the optimal strategy for modifying LaTiO₃ for photocatalytic water splitting. This study provides theoretical support for the design and optimization of perovskite-based photocatalytic materials through doping.