期刊
JOURNAL OF PHYSICS-CONDENSED MATTER
卷 17, 期 4, 页码 707-718出版社
IOP PUBLISHING LTD
DOI: 10.1088/0953-8984/17/4/013
关键词
-
Magnetic susceptibility, transport and heat capacity measurements for single-crystal NaxCoO2 (x = 0.71) are reported. A transition to a spin density wave (SDW) state at T-mag = 22 K is observable in all measurements, except chi(ac) data in which a cusp is observed at 4 K and attributed to a low temperature glassy phase. M(H) loops are hysteretic below 15 K. Both the SDW transition and low temperature hysteresis are only visible along the c-axis. The system also exhibits a substantial (similar to40%) positive magnetoresistance below this temperature. Calculations of the electronic heat capacity gamma above and below T,nag and the size of the jump in C. indicate that the onset of the SDW brings about the opening of a gap and the removal of part of the Fermi surface. Reduced in-plane electron-electron scattering counteracts the loss of carriers below the transition and as a result we see a net reduction in resistivity below T-mag. Sodium ordering transitions at higher temperatures are observable as peaks in the heat capacity with a corresponding increase in resistivity.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据