Probing the exchange coupling in the complex modified Ho-Fe-B compounds by high-field magnetization measurements

Abstract

By examining the Ho 2 Fe 14 B case, we explored the influence of substitution and absorption atoms on the high-field behavior of magnetization of rare-earth (R)-Fe intermetallics. The value of the first critical field shows that the inter-sublattice exchange interactions remain practically unchanged when the substitution takes place in the R sublattice (replacement of up to 50 % of Ho by Nd). On the contrary, hydrogen absorption by Ho 2 Fe 14 B and Ho 1 Nd 1 Fe 14 B of the maximum possible hydrogen concentration 5.5 at./f.u. decreases the strength of the R-Fe exchange by 30%. Remarkably, the influence of hydrogenation is stronger in the compound modified by substitution.