Co2+,Zn2+双掺杂铌酸锂晶体的坩埚下降法生长及其光谱特性

在LiNbO3中掺入0．1％（摩尔分数．下同）的CoO与3％，6％的ZnO，采用坩埚下降法技术生长了双掺杂的Co^2＋：Zn^2＋：LiNbO3晶体。用X射线衍射与差热分析表征了获得的晶体。测定了晶体不同部位在350～2500nm波段的吸收光谱。研究表明：Co离子位于LiNbO3晶体的崎变的氧八面体中，呈现＋2价，沿着生长方向Co^2＋在晶体中的浓度逐渐减少。ZnO的掺杂有效地抑制了Co^2＋离子在晶体中的掺入，使得Co^2＋在晶体中浓度的分布变得均匀。同时发现：ZnO的掺入使得上部晶体的熔点升高。从化学组分的角度解释了产生熔点变化的原因。观测到了750nm波长的荧光发射带。编者按]

Co2+ : Zn2+ : LiNbO3 CRYSTALS GROWN BY THE BRIDGMAN METHOD AND ITS OPTICAL SPECTROSCOPY

LiNbO3 crystals co-doped with 0.1 % (in mole, the same below) CoO and 3 %, 6 % ZnO were grown by the Bridgman method. X-ray diffraction and differential thermal analysis were used to characterize the crystals. The absorption spectra of the different parts of the crystals from 350 to 2 500 nm were measured. The results show that the Co ions are in the +2 valence present in the LiNbO3 crystal and located within the distorted oxygen octahedrons, and their concentration decreased gradually along the growth direction. The ZnO doping effectively suppresses the introduction of Co ions into the LiNbO3 crystal, and causes more homogeneous Co2+ segregation in the Co2+ : LiNbO3 crystal. With ZnO doping, the melting point of the upper side of the crystal increases. The change of the melting point of the different parts in the crystal can be explained by their chemical composition. A strong fluorescence emission band at 750 nm was observed.