摘要
以K2O为助熔剂，在较大的温度梯度（90-100℃／cm）条件下进行引种和晶体生长，应用坩埚下降法技术成功地生长出了初始Mn^2＋掺杂浓度为0．5％（摩尔分数）的近化学计量比的铌酸锂晶体。用X射线衍射表征了获得的晶体，并计算了晶体的结构参数。与同成分的铌酸锂晶体相比，样品的晶格常数略变小，紫外吸收边向短波方向发生了移动。测定了晶体的吸收与发射光谱，观测到吸收中心在571nm（6A1g（^6S）→T1g（^4G））的吸收宽带以及发光中心约620nm（^4T1g（^4G）→^5A1g（^6S））的红色荧光带。从晶体上部与下部的颜色以及吸收强度的变化，可初步推测出沿着晶体生长方向Mn^2＋离子浓度逐渐增加，Mn^2＋离子在晶体中有效的分凝系数〈1。
The near-stoichiometric LiNbO3 single crystals doped Mn^2＋ in 0.5mol% oncentration in the raw compositions were grown by the Bridgman method under the conditions of taking K2O as flux and taking high temperature gradient of about 90-100℃/cm of the interface as seeding and growing of the crystal, The X-ray diffraction （XRD） was used to characterize the crystal and the lattice structure was calculated from the result of XRD. In comparison with congruent crystal, the lattice constants become smaller, and the absorption edge was shifted to ultraviolet. The crystal absorption spectra and emission spectra were recorded, a wide absorption band centered at 571nm（6A1g（^6S）→T1g（^4G） ） and a red emission band at 620 nm（^4T1g（^4G）→^5A1g（^6S）） were observed. From the changes of absorption intensity and color of different parts,it could be deduced that the Mn^2＋ concentration increased gradually along growing direction, and it suggested that the effective distribution coefficient of Mn^2＋ in crystal was less than 1.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第11期1793-1795,1799,共4页
Journal of Functional Materials
基金
浙江省科技厅资助课题(2007C21G2070001)
浙江省教育厅科研资助课题(20061660)
