Unusual large magnetostriction in the ferrimagnet Gd2/3Ca1/3MnO3
Centro Atómico Bariloche (CNEA) and Instituto Balseiro (U. N. Cuyo) - 8400 Bariloche, Río Negro, Argentina
Accepted: 12 April 2012
We report an unusual large linear magnetostrictive effect in the ferrimagnet Gd2/3Ca1/3MnO3 (Tc≈80 K). Remarkably, the magnetostriction, negative at high temperature (T≈Tc), becomes positive below 15 K when the magnetization of the Gd sublattice overcomes the magnetization of the Mn sublattice. A rather simple model where the magnetic energy competes against the elastic energy gives a good account of the observed results and confirms that Gd plays a crucial role in this unusual observation. Unlike previous works in manganites where only striction associated with 3d Mn orbitals is considered, our results show that the lanthanide 4f-orbitals–related striction can be very important too and it cannot be disregarded.
PACS: 75.80.+q – Magnetomechanical effects, magnetostriction / 75.50.Gg – Ferrimagnetics / 75.47.Lx – Magnetic oxides
© EPLA, 2012