Magnetization reversal in orthovanadate RVO3 compounds (R=La, Nd, Sm, Gd, Er, and Y): inhomogeneities caused by defects in the orbital sector of quasi-one-dimensional orbital systems

We report on a study of various RVO3 single-crystal samples (R=La, Nd, Sm, Gd, Er, and Y) which show temperature-induced magnetization reversal. For compounds with lighter rare earths (R=La, Nd, and Sm), magnetization reversal can be observed for a magnetic field applied in the ab plane and along the c axis, whereas for the heavy rare earths (R=Gd and Er), magnetization reversal is only observed when the field is applied along the a axis. YVO3 has a magnetization reversal along all the main crystallographic axes in a modest applied field. We have found that some compounds are very sensitive to small trapped fields present in the superconducting solenoid of the magnetometer during the cooling. Based on the observed results, we argue that inhomogeniety caused by defects in the orbital sector in the quasi-one-dimensional orbital systems could account for the unusual magnetization reversal.