Effect of interstitial hydrogen and nitrogen on the magnetocrystalline anisotropy of R 2Fe 17 (R=Tb,Dy,Ho,Er)

Abstract

The magnetocrystalline anisotropies of R 2Fe 17 (R=Tb,Dy,Ho and Er) and of the nitrides and hydrides of these compounds are studied by analysing the hard and the easy magnetization curves of magnetically aligned samples in the temperature range 80–300 K. The effects of the hydrogen and the nitrogen atoms on the rare earth sublattice anisotropy are found to be opposite. It is observed that, in contrast to nitrogenation, hydrogenation leads to an easy axis type R sublattice anisotropy for R ions with negative Stevens factor α 2 (Tb, Dy and Ho). An easy-plane to easy-cone transition is detected for Dy 2Fe 17H x ( x=3 and 5). The magnetic structures of Tb 2Fe 17H x ( x=3 and 5) are possibly of the easy-cone type at room temperature.