Conduction-electron spin resonance in the superconductorK3C60
摘要:
The conduction-electron spin resonance of the superconducting fulleride compound, K3C60 (T-c = 19 K) has been observed between 2.5 and 800 K at several frequencies from 9 to 225 GHz. Between T-c and 0.7T(c) the spin lifetime of normal excitations increases as predicted by the theory of Yafet for scattering from nonmagnetic structural defects. At lower temperatures the CESR arises from states bound to vortices; here the spectrum is inhomogeneously broadened and an anomalous g shift is found. The anomalous temperature dependence of the g factor and linewidth in the normal state reported by Petit et al. is most important between 50 and 250 K, suggesting that these are related to the rotation of C-60 ions.
Abstract Structures and magnetic properties of high temperature reactionproducts of Ce metal and C60 solid have been investigated by means of X-ray diffraction and SQUID magnetometory. The X-ray diffraction patterns of relatively low temperature products show that they seem to undergo metal–ion-intercalation to C60 crystals. Unusual behaviors in the temperature dependence of the magnetization of the
摘要 利用X射线衍射和SQUID磁强计研究了Ce金属与C60固体的高温反应产物的结构和磁性能。相对低温产物的 X 射线衍射图表明它们似乎经历了金属离子嵌入 C60 晶体。产品磁化温度依赖性的异常行为揭示了铁磁性和反磁性(超导)性质的共存或竞争,其发生取决于反应温度和时间。