【摘要】 高温超导体的超声衰减峰(以及声速的改变)和内耗峰已被广泛研究,形成的机理争论很大。争论的焦点是:这些力学耗散峰是由于磁通线扩散运动还是由于其它相变等原因。作者已在文献里概括出超声衰减两种类型:钟型(衰减较缓慢)属滞弹性弛豫与λ型(衰减较迅速),并且揭示相应的相结构及其特点。同时指出:在温度比超导临界温度低的情况下Pankert超声波与涡旋线相互钉扎机制较为适用,在温度较超导临界温度高的情况,涡旋线相变模型较为适用。更多还原

【Abstract】 According to Fisher’s theory of the superconducting vortex glass,the vortex morphology model concerning the ultrasonic attenuation in the mixed state of high Tc superconductor is presented.The complex phases structure in the mixed stated of high temperature superconductors has been expounded in detail;the phase diagram for high Tc superconductor in mixed state with lower anisotropy has been shown. Two types of the ultrasonic attenuation——bell shape(attenuate more slowly)and shape(attenuate more rapidly)——are summarized.Corresponding phase structures and their characters are revealed.The results also show that Pankert’s mechanism is appropriate when temperature is lower than superconducting critical temperature,but vortex phase change mechanism is appropriate when temperature is higher than superconducting critical temperature.更多还原