Phase separation in CaCuxMn7−xO12 (x=0.38)

Abstract The crystal structure of the distorted perovskite manganite system CaCu x Mn 7− x O 12 has been investigated by using high resolution synchrotron and neutron powder diffraction for x =0.38 and 0.7. The measurements show a cubic phase at room temperature. For the system with smaller Cu content ( x =0.38), there is a phase coexistence phenomenon: below 300 K two different crystallographic phases coexist in the material. The first one is cubic and charge delocalized (CD), while the second one is trigonal and it has a charge ordering (CO) of the Mn 3+ and Mn 4+ ions. The volume fractions of both phases are about 50% each.