掺Ce稀土铁石榴石单晶的制备及磁光性能

CRYSTAL GROWTH AND MAGNETO-OPTICAL PROPERTIES OF Ce^(3+) DOPED RARE-EAWTH IRON GARNET

采用改进的助熔刑法生长块状Ｃｅ：ＹＩＧ单晶，分析了它的晶体结构、测试了在近红外波段的磁光性能Ｃｅ~３＋掺入铁石榴石十二面体位极大地增强了材料的法拉第旋转，在λ＝０．７８μｍ时，Ｙ３Ｆｅ５Ｏ１２晶体中每一个 Ｃｅ~３＋替代 Ｙ~３＋；其Ｆ的增加量（ｄθＦ，／ｄｘ）达到 ０．６×１０~４ｄｅｇ／ｃｍ，比同量 Ｂｉ~３＋替代时晶体Ｆ的增加量高２倍，在稀土铁石榴石中掺入Ｙｂ和Ｅｕ；由于其有弱的还原性，能抑制Ｃｅ~４的形成，增加 Ｃｅ^（３＋）离子的替代量。

By using the improved flux method, the bulk single crystals of Ce^3+ doped iron garnet with maximum substitutions 0.349 were prepared. The spectra of the Faraday rotation and the optical absorption were measured in the near infrared region for different Ce^3+ ions doped iron garnets. The Ce substitution prominently enhances the Faraday effect. and the enhanced Faraday rotation is as large as 0.6x 10~4deg/cm per Ce ion at = 0.78μm. which surpasses by a factor of two to the well-known MO enhancement by Bi^3+ in iron garnets at the same wavelength region. Here the different compositions of solution for maximum Ce substitution were investigated, and the Yb and Eu ion substitution for Y in the dodecahedral sites of YIG can increase the concentration of Ce^3+ ions, depress the formation of nonmagnetic Ce^4 ions by the charge compensation.