A detailed study of the complex magnetic behaviour of the La0.5Bi0.2Ca0.3MnO3 perovskite and its relation with the magnetic structure of this compound is presented. At low temperatures the initial magnetization curve shows two metamagnetic-like steps at 2.5 and 5 T applied magnetic fields that are indicative of field-induced AF --> FM transitions, both irreversible. The curves recorded from 75 K and up to 150 K turn out to be highly hysteretic after reaching the saturation field for the first time. For higher temperatures, the ferromagnetic character of the samples as well as the effect of any antiferromagnetic interaction quickly disappears. The results obtained by neutron diffraction experiments indicate the coexistence of ferro- and antiferromagnetic interactions. We conclude that this compound has a low temperature FM ground state but, as the temperature decreases, freezes in an AF/FM metastable structure that is overcome by an applied magnetic field of at least 2.5 T.
Anomalous hysteresis and metamagnetism in Bi substituted perovskites / Barandiaran, J. M.; Gutierrez, J.; Rodriguez, J.; Fernandez, J. R.; Amboage, M.; Righi, L.. - In: PHYSICA. B, CONDENSED MATTER. - ISSN 0921-4526. - 343:(2004), pp. 379-383. [10.1016/j.physb.2003.08.073]
Anomalous hysteresis and metamagnetism in Bi substituted perovskites
L. RIGHI
2004-01-01
Abstract
A detailed study of the complex magnetic behaviour of the La0.5Bi0.2Ca0.3MnO3 perovskite and its relation with the magnetic structure of this compound is presented. At low temperatures the initial magnetization curve shows two metamagnetic-like steps at 2.5 and 5 T applied magnetic fields that are indicative of field-induced AF --> FM transitions, both irreversible. The curves recorded from 75 K and up to 150 K turn out to be highly hysteretic after reaching the saturation field for the first time. For higher temperatures, the ferromagnetic character of the samples as well as the effect of any antiferromagnetic interaction quickly disappears. The results obtained by neutron diffraction experiments indicate the coexistence of ferro- and antiferromagnetic interactions. We conclude that this compound has a low temperature FM ground state but, as the temperature decreases, freezes in an AF/FM metastable structure that is overcome by an applied magnetic field of at least 2.5 T.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
