Magnetic properties of YVO3 from susceptibility and Y-89 NMR measurements

The magnetic properties of YVO3, a prototype of highly correlated d-electron Mott-Hubbard antiferromagnetic (AF) orthovanadates, are studied by means of magnetization and susceptibility measurements, coupled to Y-89 NMR spectra and relaxation. Both field-cooled and zero-field-cooled conditions are considered. The history and field-dependent properties recently reported for the AF phases below T-N similar or equal to 113 K and T-N'similar or equal to 77 K are confirmed. The behavior in the paramagnetic phase and around TN is Studied and it is shown how the field-induced short range order and canted-spin weak ferromagnetism is quenched in strong field, yielding (M/H)(ZFC)similar or equal to(M/H)(FC) for H similar or equal to 6 T. At variance with the susceptibility in strong field, the Y-89 NMR line width shows a divergent behavior for T-->T-N(+). The Y-89 relaxation rates do not display, for T-->T-N(+), the behavior expected for spin fluctuations of AF-ferromagnetic (FE) symmetry as the one in the ordered state, possibly in view of the quasistatic character of the short range order. (C) 1997 American Institute of Physics.