A-site ordered perovskite CaCu3Cu2Ir2O12−δ with square-planar and octahedral coordinated Cu ions
Zhao Qing1, 2, Yin Yun-Yu2, Dai Jian-Hong2, Shen Xi2, Hu Zhi-Wei3, Yang Jun-Ye2, Wang Qing-Tao1, 4, †, , Yu Ri-Cheng2, Li Xiao-Dong5, Long You-Wen2, 6, ‡,
       

Heat capacity as a function of temperature for CaCu3Cu2Ir2O12−δ. The inset shows the fitting result described in the text. The open circles represent experimental data, and the red curve is the fitting result.