Mesoscopic phase separation in Na${}_x$CoO${}_2$ ($0.65\le x\le 0.75$)

P. Carretta, M. Mariani, C. B. Azzoni +5

NMR, EPR and magnetization measurements in Na${}_x$CoO${}_2$ for $0.65\le x\le 0.75$ are presented. While the EPR signal arises from Co${}^{4+}$ magnetic moments ordering at $T_c\simeq…