Magnetic reconstructions in B-site doped manganites

摘要

The magnetic nature of the B-site dopants controls the magnetic phases in B-site doped manganites RE_(1-x)AE_xMn_(1-η)B_ηO_3. Different B-site dopants of equal valence, doped into the same reference manganite, lead to different magnetic phases at low temperature, which cannot be explained using the valence change scenario. We focus on trivalent B-site dopants in CE-CO-OO-I (CE-type antifer-romagnet; CO: charge order; 00: orbital order, I: Insulator) manganites at half-filling x = 0.50 to study the role of magnetic interactions between the B-site dopants and the neighboring Mn-sites by using a two-orbital double-exchange model including super-exchange interactions, Jahn-Teller lattice distortions, and substitutional disorder in two dimensions. We show that the magnetic reconstructions around the B-site dopants due to the modified double-exchange and super-exchange interactions control the phase competition in B-site doped manganites.