Magnetic and superconducting phase diagram in oxybromite cuprate Ca2-xNaxCuO2Br2

A comprehensive magnetic and superconducting phase diagram determined by muon spin rotation/relaxation (μSR) is presented for Ca 2-x Na x CuO 2 Br 2 which has apical bromine atoms. Evidence for antiferromagnetic (AF) order in lightly doped samples and that for quasi-static spin glass (SG)-like state in moderately doped ones are obtained by ZF-μSR at low temperatures. While the phase diagram is qualitatively similar to that in typical 2-1-4 cuprates including Ca 2-x Na x CuO 2 Cl 2 and La 2-x Sr x CuO 4 , it exhibits a slight shift (expansion) over the x axis.