Low-temperature elastic moduli and dilational and shear internal frictions of superconducting ceramic GdBa2Cu3O7- delta.
Low-temperature elastic moduli and dilational and shear internal frictions of superconducting ceramic GdBa2Cu3O7- delta.
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超导陶瓷GdBa2Cu3O7-δ的低温弹性模量以及膨胀和剪切内耗。
DOI：
10.1103/physrevb.49.13099
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Sanpei
中科院分区：
文献类型：
--
作者：
Fukuhara;Sanpei
在高温超导体 GdBa2Cu307 z 中，同时测量了室温至 77 K 之间的纵向和横向波速、六种弹性参数以及膨胀和剪切内耗作为温度的函数。体积模量和 Lame 参数从 117 K 开始突然增加表明，与保持体积的畸变相比，有序参数与不保持体积的畸变的耦合要强得多。膨胀摩擦的 227 和 120 K 峰值可能分别与由于势能变化引起的结构变化和二级相变有关。对于剪切摩擦，214 K 和 106 K 峰可分别归因于表观活化能为 0.62 eV 的钡原子弛豫和晶格不稳定性。
Longitudinal and transverse wave velocities, six kinds of elastic parameters, and dilational and shear internal frictions have been simultaneously measured as functions of temperature between room temperature and 77 K in the high-T, superconductor GdBa2Cu307 z. An abrupt increase from 117 K in bulk modulus and Lame parameter suggests that the order parameter has a much stronger coupling with volume-nonpreserving distortions than with volume-preserving distortions. The 227 and 120 K peaks in dilational friction might be related to structural change and second-order phase transition due to variation of potential energy, respectively. For shear friction, the 214 and 106 K peaks could be attributed to barium atom relaxation with an apparent activation energy of 0.62 eV, and lattice instability, respectively.