Random potential effect near the bicritical region in perovskite manganites as revealed by comparison with the ordered perovskite analogs.
The orbital-charge-spin ordering phase diagram for half-doped perovskites Ln(1/2)Ba(1/2)MnO3 (Ln = rare earth) with ordered Ln/Ba cations has been investigated comparatively with that of the Ln/Ba solid-solution analogs. A large modification of the phase diagram is observed upon the A-site disordering near the original bicritical point between the charge-orbital ordering and ferromagnetic metallic phases. The random potential by quenched disorder inherent in the A-site solid solution is found to suppress the respective long-range orders and gives rise to the colossal magnetoresistive state.
Akahoshi
D
D
Correlated Electron Research Center, Advanced Industrial Science and Technology, Tsukuba 305-8562, Japan.
Uchida
M
M
Tomioka
Y
Y
Arima
T
T
Matsui
Y
Y
Tokura
Y
Y