Electrical and Structural Properties and Phase Diagram of a Molecular Superconductor β-[(CH3)4N][Pd(dmit)2]2
Electrical and Structural Properties and Phase Diagram of a Molecular Superconductor β-[(CH3)4N][Pd(dmit)2]2
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分子超导体 β-[(CH3)4N][Pd(dmit)2]2 的电学和结构特性及相图
DOI：
10.1246/bcsj.71.997
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发表时间：
1998
影响因子：
4
通讯作者：
H. Kobayashi
中科院分区：
文献类型：
--
作者：
A. Kobayashi;A. Miyamoto;R. Kato;A. Sato;H. Kobayashi
β-[(CH3)4N][Pd(dmit)2]2与[(CH3)4N][Ni(dmit)2]2同构，是第一个表现出超导跃迁的纯π受体分子导体。研究了β-[(CH3)4N][Pd(dmit)2]2在低温下的晶体结构、电阻率和磁化率的压强依赖性。β-[(CH3)4N][Pd(dmit)2]2相图的一般特征与有机超导体相图相似。在常压下，电阻率随温度的降低而逐渐增大。在6 - 9kbar时观察到超导转变。最高温度为6.5 K。在5 ~ 6.3 kbar之间，在超导过渡偏置温度以上的小温度范围内，观察到电阻率的快速下降。虽然电阻率不为零，但该温度区域可视为“预超导区”。在9kbar以上，金属状态稳定到低温。在5kbar以上，大部分晶体呈现电阻率异常。
β-[(CH3)4N][Pd(dmit)2]2 is isomorphic to [(CH3)4N][Ni(dmit)2]2, which is the first pure π acceptor molecular conductor exhibiting a superconducting transition. The crystal structure at low temperature, pressure dependence of the resistivity and the magnetic susceptibility of β-[(CH3)4N][Pd(dmit)2]2 were examined. The general features of the phase diagram of β-[(CH3)4N][Pd(dmit)2]2 resemble those of the organic superconductors. At ambient pressure, the resistivity increases gradually with lowering temperature. A superconducting transition was observed at 6—9 kbar. The highest Tc was 6.5 K. Between 5 and 6.3 kbar, a characteristic rapid resistivity decrease was observed at the small temperature range above the offset temperature of the superconducting transition. Although the resistivity is not zero, this temperature region can be regarded as a “pre-superconducting region.” Above 9 kbar the metallic state is stabilized down to low temperature. Above 5 kbar, most of the crystals exhibited resistivity anomali...