Unusual large magnetostriction in the ferrimagnet Gd(2/3)Ca(1/3)MnO3

V. F. CORREA; N. HABERKORN; G. NIEVA; D. J. GARCIA; B. ALASCIO

EUROPHYSICS LETTERS

EPL ASSOCIATION

Lugar: Bristol; Año: 2012 vol. 98 p. 370031 - 370036

0295-5075

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 15K 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.