非晶态快离子导体(AgI)x(Ag4P2O7)1-x的声学性质

用液氮骤冷方法制备了(AgI)_x(Ag₄P₂O₇)_1-x系列非晶态快离子导体。对AgI摩尔浓度x=0.50,0.60,0.67,0.75,0.80的样品,在77—300K温度范围及2,5,10,15MHz的频率上测量了纵波和横波的超声衰减和声速。发现在200—240K附近存在一个异常强的弛豫型超声吸收峰,随AgI含量的增加,该峰的位置向低温方向移动,且峰的高度增大。在实验的温度范围内,观察到纵波和 关键词：

ACOUSTIC PROPERTIES OF AMORPHOUS SUPERIONIC CONDUCTOR (AgI)x(Ag4P2O7)1-x

Amorphous superionic conductor (AgI)_x(Ag₄P₂O₇)_1-x system has been obtained by means of the liquid nitrogen rapid quenching technique. The ultrasonic attenuation and velocity of longitudinal and transverse sound waves in the samples for Agl with mol concentration x = 0.50, 0.60, 0.67, 0.75, 0.80 were measured in the temperature range 77-300 K at the frequency of 2, 5, 10, 15 MHz. An anomalous strong ultrasonic absorption peak is observed at a temperature around 200-240 K with the rharacteristics of relaxation attenuation evidently. The attenuation peak was found to shifts to lower temperature and the peak attenuation value increases with increasing Agl content. In the experimental temperature region the internal friction Q_M^-1 of longitudinal and transverse waves in the samples is almost equivalent. In the course of attenuation measurements the sound velocity, elastic moduli at room temperature and the dependence of sound velocity on Agl content were also measured. The experimental data fit satisfactorily the unified theory of low frequency fluctuation, dissipation and relaxation process (i.e. infrared divergence response theory, briefly called as IDR) proposed by Ngai. The apparent activation energy and infrared divergence exponent of the samples were presented.