Abstract:
Properties of thin films of hole-doped Pr0.6Ca0.4MnO3 and electron-doped Pr0.4Ca0.6MnO3 are compared. While both are charge-ordered insulators, the hole-doped manganate undergoes an insulator-metal (I-M) transition on the application of magnetic-fields, but the electron-doped manganate does not. Substitution of 3% Cr3+ Or Ru4+ in the Mn site has greater effect on the hole-doped manganate. Electrical fields, however, have similar effects on the hole-doped and electron-doped manganates, both exhibiting current-induced I-M transitions. The study not only establishes that the mechanism of the I-M transition brought about by electric and magnetic fields are different, but also suggests that the electronic structures of the hole-doped and electron-doped manganates have basic differences. (C) 2001 Elsevier Science Ltd. All rights reserved.
