【摘要】 本文研究了掺铌钨酸锌单晶的生长特性,该种晶体对生长方向、籽晶质量和扩肩速度很敏感,测定了铌的有效分凝系数K_eff=1.1。对掺铌钨酸锌单晶的去色机制进行了深入的探讨,提出由于氧空位导致ZnWO₄单晶中色心的存在,而氧空位的产生是由于W—O键较弱,高温下WO_?八面体容易失去氧离子所致。还测定了该晶体的能量分辨率和衰减时间,对漂移特性亦进行了初步的测定。已用提拉法生长出无色透明的大块掺铌钨酸锌单晶。更多还原

【Abstract】 Growth characteristics of Nb⁵⁺: ZnWO₄ single crystal were Investigated. Crystal growth of Nb⁵⁺: ZnWO₄ is highly sensitive to growth direction, quality of seed crystal and rate of shouldering. The effective segregation coefficient of Nb⁵⁺ is K_eff=1.1. Fading mechanism of Nb⁵⁺ ZnWO₄ single crystal was further dlscussed. It is suggested that the existence of colour centre in ZnWO₄ single crystal results from the oxygen vacancies produced by losing of oxygen ions from the atomic group WO₆ at high temperature because of the weak strenth of the bond W—O. The energy resolution of the crystal was measured by X-rays from a ¹³⁷Cs source. The decay time distribution for Nb⁵⁺: ZnWO₄ single crystal was measured by means of the single photon counting method. Three decay time were obtained. Shift characteristics of the crystal were also measured. Colourless, transparent, bulk crystal was obtained by use of Czochralski technique.更多还原