Conduction-electron-spin resonance in organic conductors: alpha and beta phases of di
Conduction-electron-spin resonance in organic conductors: alpha and beta phases of di
复制标题
有机导体中的传导电子自旋共振：二元的α相和β相
DOI：
10.1103/physrevb.34.117
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Kinoshita
中科院分区：
文献类型：
--
作者：
Sugano;Saito;Kinoshita
在5 ~ 300 K温度范围内，双（乙撑二硫基）四硫富瓦烯三碘化物[（BEDT-TTF）2 I3] α和β相单晶的电子自旋共振g值、线宽、线形和自旋磁化率均具有明显的温度和角度依赖性.在这两个阶段中，在室温下观察到的Dysonian线形特征的导电电子自旋共振时，微波电场施加平行于准二维导电平面的晶体。在适当晶体尺寸的β-（BEDT-TTF）_2I_3超导相中，当微波电场垂直于平面时，室温下观察到的洛伦兹线形随温度的降低逐渐转变为Dysonian线形。这些现象进行了讨论，比较来自反射光谱和电导率测量的传输参数。α和β相的自旋扩散常数估计分别约为0.2和0.3 cm 2 s-1。这些常数与通过反射光谱分析独立评估的载流子扩散常数一致。对于α相，g值和线宽随温度的变化表明三碘离子与BEDT-TTF离子之间存在强烈的相互作用，且这种相互作用的大小随金属-绝缘体转变而突变。
The electron-spin resonance g value, linewidth, line shape, and spin susceptibility of single crystals of the α and β phases of di [bis (ethylenedithiolo) tetrathiafulvalene] triiodide [(BEDT-TTF) 2 I 3] are each found to show marked temperature and angular dependences in the temperature range from 5 to 300 K. In both phases, a Dysonian line-shape characteristic of conduction-electron-spin resonance is observed at room temperature when the microwave electric field is applied parallel to the quasi-two-dimensional conducting plane of the crystal. In the superconducting phase of β-(BEDT-TTF) 2 I 3 with appropriate crystal size, it is found that when the microwave electric field is applied perpendicular to the plane a Lorentzian line shape observed at room temperature is gradually converted to a Dysonian line shape with decreasing temperature. These phenomena are discussed in comparison with the transport parameters derived from the reflectance spectra and the conductivity measurements. The spin diffusion constants in the α and β phases are estimated to be about 0.2 and 0.3 cm 2 s− 1, respectively. These constants are in agreement with the carrier diffusion constants evaluated independently by the analysis of the reflectance spectra. For the α phase, it is suggested from the temperature dependences of the g value and linewidth that there is a strong interaction between the triiodide and BEDT-TTF ions and the magnitude of the interaction changes suddenly with the metal-insulator transition.