论文部分内容阅读
应用坩埚下降法,以同成分化学摩尔分数比(Li2O:48.6%,Nb2O5:51.4%)为原料,以CoO作为掺杂物,在合适的温度梯度(20~40℃/cm)与生长速度(1~3mm/h),生长出了Co2+掺杂摩尔分数分别为0.1%与0.3%的LiNbO3(LN)晶体。用X射线衍射(XRD)与差热分析(DTA)表征了获得的晶体。测定了不同部位晶体从350~2500nm的吸收光谱。观测到520nm,549nm与612nm三个分裂的尖吸收峰以及以1358nm为发光中心的吸收带。从吸收特性表明,Co离子掺杂于畸变的氧八面体中,呈现+2价态,并且沿着晶体生长方向浓度逐渐减少,Co2+在LiNbO3晶体中的有效分凝系数大于1。研究了不同部位晶体在900nm以下的荧光光谱特性,在750nm发现有较强的荧光发射,并随着激发波长的增长,荧光发生红移。
Using the method of crucible dropping, using the same molar fraction of chemical composition (Li2O: 48.6%, Nb2O5: 51.4%) as raw material and CoO as a dopant, 1 ~ 3mm / h), LiNbO3 (LN) crystals with Co2 + doping mole fractions of 0.1% and 0.3%, respectively, were grown. The obtained crystals were characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The absorption spectra of the crystals from 350 to 2500 nm were measured. The sharp peaks at 520 nm, 549 nm and 612 nm were observed and the absorption band centered at 1358 nm. From the absorption characteristics, it is shown that the Co ions doping in the distorted octahedron presents a +2 valence state, and the concentration gradually decreases along the crystal growth direction. The effective segregation coefficient of Co2 + in the LiNbO3 crystal is greater than one. Fluorescence spectra of different parts of the crystal below 900 nm were studied. Strong fluorescence emission was found at 750 nm. Fluorescence was red-shifted with increasing excitation wavelength.