Molecular structure of a crystal phase coexisting with kappa -(BEDT-TTF)2Cu(NCS)2 studied by scanning tunneling microscopy.
Molecular structure of a crystal phase coexisting with kappa -(BEDT-TTF)2Cu(NCS)2 studied by scanning tunneling microscopy.
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通过扫描隧道显微镜研究与 kappa -(BEDT-TTF)2Cu(NCS)2 共存晶相的分子结构。
DOI：
10.1103/physrevb.50.15427
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Saito
中科院分区：
文献类型：
--
作者：
Shigekawa;Miyake;Oigawa;Nannichi;Môri;Saito
通过扫描隧道显微镜（STM）发现，在室温下生长的(BEDT-TTF ${)}_{2}$ Cu（NCS ${)}_{2}$）晶体中，除了在\ensuremath{\sim} 10 K时具有金属-超导体相变的众所周知的\ensuremath{\kappa}相外，还存在一种分子结构。所得相的二维结构与先前报道的\ensuremath{\alpha} -(BEDT-TTF ${)}_{2}$ Cu（NCS ${)}_{2}$）晶体在\ensuremath{\sim} 200 K下具有金属绝缘体转变的电荷转移盐接近。STM测量的I-V（隧道电流\char 21偏置电压）曲线的温度依赖性显示了两种相变特性。{}在两个BEDT-TTF分子结合形成的相中，还观察到由电荷密度调节形成的具有2个\ifmmode\times\else\texttimes\fi{} 2个单位胞的上层结构。
By using scanning tunneling microscopy (STM), a molecular structure was found to coexist in a (BEDT-TTF${)}_{2}$Cu(NCS${)}_{2}$ crystal grown at room temperature, in addition to the well-known \ensuremath{\kappa} phase with metal-superconductor phase transition at \ensuremath{\sim}10 K. The obtained two-dimensional structure of the phase was close to that of the \ensuremath{\alpha}-(BEDT-TTF${)}_{2}$Cu(NCS${)}_{2}$ crystal previously reported as a charge-transfer salt with metal-insulator transition at \ensuremath{\sim}200 K. The temperature dependence of I-V (tunneling current\char21{}bias voltage) curves measured by STM showed both phase transition properties. A superstructure with a 2\ifmmode\times\else\texttimes\fi{}2 unit cell formed by modulated charge density on the BEDT-TTF molecules was also observed for the phase, which was formed by uniting two BEDT-TTF molecules.