Magnetic studies of rare-earth tungstates

Measurement of magnetic susceptibility (χ_m) of rare-earth tungstates RE₂(WO₄)₃ with RE = Gd, Tb, Dy, Ho, Er, Tm and Yb have been reported in the temperature range 3–300 K at a magnetic field of 3.2 × 10⁵ Am^-1. All the tungstates are found to be ferrimagnetic with a ferrimagnetic Curie-temperature lying in the range 15–27 K. Evaluated magneton numbers agree fairly well with free tripositive rare-earth ions. The results are discussed on the basis of a new proposed model. Except for Tb all the evaluated parameters have systematic variation over the entire rare-earth series.