同位素7LiNbO3晶体的生长工艺研究

Growth Process Research of Isotope ~7LiNbO_3 Crystal

以Nb2O5和7LiOH为原料,通过多次烘料、制备多晶料和晶体生长等过程,探索生长高质量的同位素7LiNbO3晶体的生长工艺,为实现中子散射技术更好地分析铌酸锂晶体的微观结构提供条件。通过紫外吸收边法测得生长的晶体组分为7Li%=47.47%,由于7LiOH的不稳定性,晶体组分偏离同成分点（48.4%）较大。差热（DTA）分析结果表明晶体的熔点为1218℃。热重（TG）分析结果表明晶体在室温至1250℃范围内稳定,无质量变化。透过光谱分析结果表明晶体在5003200 nm波段平均透过率达75%。

In Nb_2O_5 and ~7LiOH as raw materials,through several process of sintering materials polycrystalline material preparation and crystal growth etc.The crystal growth technique of isotope LiNbO_3 crystal with good quality were explored,which can provide good condition for better investigation on the defects structure of lithium niobate crystal by neutron scattering technique.The crystal content of as-grown crystal measured by UV-absorption edge method is ~7Li%= 47.47%,which produces large deviation from congruent point(48.4%) result from the instability of LiOH.Differential scattering calorimetry(DTA) results show that the melting point of as-grown crystal is 1218 ℃.Thermalgravimetric(TG) results indicate the crystal is stable over the room temperature to 1250 ℃ with no mass variation.The transmission spectrum results show that the average transmittance of as-grown crystal reaches to 75%in the range of 500-3200 nm.