论文部分内容阅读
测试了镁铁双掺杂ＬｉＮｂＯ＿３晶体的紫外－可见和红外吸收谱，发现掺镁阈值以下的晶体在４８２．５ｎｍ处有一小吸收峰，认为是由晶体场引起的Ｆｅ离子ｄ－ｄ禁戒跃迁所至。在掺镁超过阈值的晶体中此峰趋于消失，说明Ｆｅ￣（３＋）离子在掺镁阈值前后所处的晶体场发生了变化，进而推测铁离子的占位发生了变化．结合ＯＨ￣－谱３５０４ｃｍ￣（－１）吸收带的出现，进一步说明了阈值以上Ｆｅ进入了Ｎｂ位。
The UV-Vis and IR spectra of Mg-Fe-doped LiNbO_3 crystals were tested. It is found that there is a small absorption peak at 482.5 nm in the crystals below the Mg-doped threshold, which is considered as the d-d forbidden transition of Fe ions induced by the crystal field To all. This peak tends to disappear in the crystal with magnesium exceeding the threshold value, indicating that the crystal field of the Fe 3+ ion before and after the magnesium doping threshold has been changed, and then it is speculated that the occupancy of the iron ion has changed. Combined with the appearance of the 3504 cm ~ (-1) absorption band of the OH ~ -pectra, it is further demonstrated that above the threshold, Fe enters the Nb site.