MAGNETISM IN TRANSITION-METAL HYDRIDES

Using lattic parameters determined by total energy calculations we have performed calculations of the band structure for all the 3d, 4d and 5d monohydrides in the NaCl structure. The results of these calculations are used to evaluate the Stoner criterion for ferromagnetism. We predict one strong candidate for ferromagnetism, i.e. CoH which exceeds by far the Stoner limit and two other hydrides, i.e. FeH and RhH which come close to the limit. In agreement with our results recent Mossbauer studies have shown that an f.c.c. gamma-CoH(x) with x > 0.9 becomes ferromagnetic at hydrogen pressures near 9 GPa. Similar experiments demonstrate ferromagnetism in the h.c.p. phase of FeH. We offer these results as another example of success of the local density theory in predicting properties of materials.