A new method for changing the volume concentration of hydrogen in congruent LiTaO (lithium tantalate, LT) crystals has been studied. It has been established that pre-treatment of the sample in adipic acid significantly increases the volumetric concentration of hydrogen in the sample during subsequent annealing in a humid atmosphere at a relatively low annealing temperature. First of all, this preserves the LT single crystal in a single-domain state. In contrast to known methods for increasing the volumetric concentration of hydrogen, the proposed method affects the absorption coefficient of the sample in the optical range less than for a congruent LiNbO crystal. It has been shown that the type of IR absorption spectrum of OH groups and the defect structure of the LT crystal significantly depend on the volume concentration of hydrogen in the sample. The study also analyzed the reasons for this effect. The temperature dependences of the electrical conductivity of LT samples with different hydrogen concentrations have been studied. It has been shown that the type of electronic conductivity of LT samples changes when the concentration of OH groups in the crystal increases significantly.

中文翻译：

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氢体积浓度对同质LiTaO3晶体红外吸收光谱精细结构和电导率特征的影响

研究了一种改变同成分LiTaO（钽酸锂，LT）晶体中氢体积浓度的新方法。已经确定，在随后在潮湿气氛中以相对低的退火温度进行退火期间，在己二酸中对样品进行预处理显着增加了样品中氢的体积浓度。首先，这使LT单晶保持在单畴状态。与已知的增加氢体积浓度的方法相比，所提出的方法对光学范围内样品的吸收系数的影响小于同质 LiNbO 晶体的吸收系数。研究表明，OH基团的红外吸收光谱类型和LT晶体的缺陷结构显着取决于样品中氢的体积浓度。研究还分析了造成这种影响的原因。研究了不同氢浓度的 LT 样品电导率的温度依赖性。研究表明，当晶体中 OH 基团的浓度显着增加时，LT 样品的电子电导率类型会发生变化。