Phase separation over an extended compositional range: Studies of theCa1−xBixMnO3(x<~0.25)phase diagram

Phase transitions on the electron-doped side of the Ca{sub 1-x}Bi{sub x}MnO{sub 3} system (x{ =}x{ge}0.03, is characterized by the absence of charge and orbital ordering, a canted G-type antiferromagnetic spin structure, and delocalized electron transport. The second phase, observed from 0.25{&gt;=}x{ge}0.12 (single phase at x=0.18), is characterized by pronounced orbital ordering, a C-type antiferromagnetic spin structure, and insulating behavior. The third low-temperature phase, observed for x{&gt;=}0.20, is characterized by orbital and magnetic ordering similar to the Wigner crystal structure previously observed for Ca{sub 0.67}La{sub 0.33}MnO{sub 3}, but with a 4axbx2c unit cell. The most striking feature of the phase diagram is the wide compositional range over which low-temperature phase separation is observed. Only those samples with x