掺铋钇铁石榴石磁光陶瓷的热压烧结及其性能研究

钇铁石榴石(Y₃Fe₅O₁₂, YIG)材料因其优异的磁性能和磁光性能在微波通信、激光技术和光纤通讯等领域具有重要应用。离子掺杂是提高YIG材料磁光性能的有效途径之一, 本研究选择离子半径适配的Bi³⁺掺杂改性YIG陶瓷以提高材料的磁光性能。本工作采用固相法热压烧结制备Bi_xY_3-xFe₅O₁₂ (x=0、0.3、0.6、0.9)陶瓷, 并研究Bi³⁺掺杂对YIG陶瓷材料相结构、微观形貌、红外透过性、磁性能以及磁光性能的影响。结果表明: 陶瓷样品均呈石榴石立方相结构; 显微结构致密, Bi³⁺掺杂后晶粒尺寸不同程度增大; 样品红外透过率良好, 随Bi³⁺掺杂量增大而降低; 陶瓷样品的法拉第旋转角随Bi³⁺掺杂量增加呈线性变化, Bi³⁺掺杂量每增加1% (原子分数), 在波长1064 nm和1550 nm处变化量分别约为-49.0 (°)/cm和-30.2 (°)/cm。Bi_0.6Y_2.4Fe₅O₁₂陶瓷样品在1064 nm和1550 nm波长下法拉第旋转角分别达到-703.3 (°)/cm和-461.5 (°)/cm, 绝对值远高于未掺杂YIG陶瓷的277.6 (°)/cm和172.0 (°)/cm。由此可见, 掺杂适量Bi³⁺可以显著增强YIG陶瓷材料的磁光性能。

Microstructure and Properties of Bi-doped Yttrium Iron Garnet Magneto-optical Ceramics Prepared by Hot-pressing Sintering Process

Yttrium iron garnet (Y₃Fe₅O₁₂, YIG) materials with excellent magnetic and magneto-optical performances have been widely used in various fields such as the microwave communication, laser technology and optical fiber communication. Ion doping is considered as an effective method to improve the magneto-optical performance of YIG materials. In this study, Bi³⁺ with appropriate ion radius were selected to modify YIG ceramics to improve the magneto-optical properties of the materials. A series of Bi_xY_3-xFe₅O₁₂ (x=0, 0.3, 0.6, 0.9) ceramics were prepared by the hot-pressing sintering process with the solid-state reaction. Phase structure, micro-morphology, infrared transmittance, magnetic and magneto-optical properties of the sintered Bi_xY_3-xFe₅O₁₂ (x=0, 0.3, 0.6, 0.9) ceramics were investigated. All sintered Bi³⁺-doped YIG ceramic samples exhibit the pure garnet phase structure with dense microstructure, and the grain size increases with Bi³⁺ doping. The infrared transmittance of the sample is good, but it decreases with the increase of Bi³⁺ doping content. The Faraday rotation angle of the YIG ceramic sample changes linearly with the Bi³⁺ content increase. When the Bi³⁺ content increases about 1% (in atom), Faraday rotation angle changes about -49.0 (°)/cm and -30.2 (°)/cm at 1064 nm and 1550 nm wavelengths, respectively. Faraday rotation angles of Bi_0.6Y_2.4Fe₅O₁₂ ceramic sample at wavelengths of 1064 nm and 1550 nm are -703.3 (°)/cm and -461.5 (°)/cm, respectively, which are much higher than that of the undoped YIG ceramics (277.6 (°)/cm and 172.0 (°)/cm, respectively). The magneto-optical performance of YIG ceramics is enhanced obviously by the Bi³⁺ doping.