MAGNETIC-BEHAVIOR OF THE ANTIFERROMAGNET FETA2O6

The magnetic behaviour of the antiferromagnet FeTa2O6 was investigated through heat capacity, magnetic susceptibility and magnetization meas urements. The broad magnetic susceptibility curve (peaked at 15 K) pre sents an inflection typical of two-dimensional systems. This inflectio n is observed near 10 K, the temperature at which early reported Mossb auer measurements indicate the onset of magnetic order. The heat capac ity measurements have shown a clear transition at 8.7 K, where Mossbau er measurements show complete ordering. Magnetization curves, for temp eratures between 1.4 K and 5 K, display a noticeable change in slope, suggesting a spin-flop transition induced by a field higher than 10 T. It is argued that this transition, which disappears for T > 6 K, is e vidence of two-dimensional behaviour.