Unusual coexistence of negative/positive charge-transfer in mixed-valence Na${}_x$Ca${}_{1-x}$Cr${}_2$O${}_4$

M. Taguchi, H. Yamaoka, Y. Yamamoto +6

We have investigated the electronic structure of Na${}_x$Ca${}_{1-x}$Cr${}_2$O${}_4$ using x-ray absorption spectroscopy together with Anderson impurity model calculations with full multip…