  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 magnetic field applied in the ab plane and along the c
axis, whereas for the heavy rare-earths (R = Gd, 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.
