1109.0259 (V. F. Correa et al.)

Unusual giant magnetostriction in the ferrimagnet
Gd$_{2/3}$Ca$_{1/3}$MnO$_3$    [PDF]

V. F. Correa, N. Haberkorn, G. Nieva, D. J. Garcia, B. Alascio

We report an unusual giant linear magnetostrictive effect in the ferrimagnet Gd$_{2/3}$Ca$_{1/3}$MnO$_3$ ($T_{c} \approx$80 K). Remarkably, the magnetostriction, negative at high temperature ($T \approx T_{c}$), becomes positive below 15 K when the magnetization of the Gd sublattice overcomes the magnetization of the Mn sublattice. A rather simple model where the magnetic energy competes against the elastic energy gives a good account of the observed results and confirms that Gd plays a crucial role in this unusual observation. Unlike previous works in manganites where only striction associated with 3$d$ Mn orbitals is considered, our results show that the lanthanide 4$f$ orbitals related striction can be very important too and it cannot be disregarded.

View original: http://arxiv.org/abs/1109.0259