Critical behavior of the ferromagnetic perovskites RTiO3 (R = Dy, Ho, Er, Tm, Yb) by magnetocaloric measurements

Ferromagnetism in perovskites RTiO3 can be induced by a steric effect. The way in which the subtle local structural change can induce three-dimensional (3D) ferromagnetic coupling through Ti-O-Ti superexchange interactions remains controversial. A critical behavior study for the ferromagnetic phase has been made so far only on YTiO3 because the magnetization measurements are plagued by the contribution from the magnetic rare earth. Here we report critical exponents for most ferromagnetic members in the RTiO3 family by measuring the magnetocaloric effect and applying the corresponding scaling laws. Our results indicate that the ferromagnetic coupling in the RTiO3 can be well described by the 3D Heisenberg model.