The metallic phase in potassium fullerides KxC70 was researched using electrical resistivity measurements in the case of film samples and magnetic susceptibility measurements in the case of powder samples. The K concentration dependence of the electrical resistivity of the KxC70 film at 423 K showed two minima: namely, 1.0×10−1 and 6.1×10−3 Ω cm at x=1.1 and 4.1, respectively. The temperature dependence of the resistivity of the K4C70 film showed a disordered-metallic behavior. Superconducting quantum interference device (SQUID) measurements for K4C70 powder revealed a temperature-independent magnetic susceptibility contribution of 3.47×10−4 emu/mol. This contribution was attributed to Pauli paramagnetism, and it was also observed in electron spin resonance (ESR) measurements. Futhermore, ESR spectra for K4C70 powder showed that the linewidth broadened with increasing temperature. It was clearly established that K4C70 is a metallic phase in KxC70. The crystal structure of K4C70 was found to be simple tetragonal with a=1.266 nm and c=1.098 nm. No superconductivity was observed in K4C70 above 2 K.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2003 Jul 15|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics