Magnetic properties of Y0.7Er0.3Fe2(H,D)4.2 compounds under continuous magnetic field up to 35 tesla

Abstract

The study of the Y0.7Er0.3Fe2(H,D)4.2 shows that the Y for Er substitution modifies both structural and magnetic properties of the hydrides and deuterides. Their cell volume is smaller than for the nonsubstituted compounds. Under high magnetic field two field-induced transitions are observed, the first one that takes place between 4.2 and 26 K (hydride) and 53 K (deuteride) originates from the erbium magnetic behavior, the second one found above 101 K (hydride) and 60 K (deuteride) is mainly attributed to an antiferro-ferromagnetic transition in the Fe sublattice. This important isotopic effect is attributed to the change of the cell volume induced by the deuterium and hydrogen insertion. Comparison with YFe2H4.2 and YFe2D4.2 compounds shows that the temperature at which appears the second transition is shifted to lower values. The transition field increases linearly versus temperature but with a much larger ΔHTR/ΔT slope for the deuteride compared to the hydride whereas there were similar in the nonsubstituted compounds. The roles of both cell volume change and erbium magnetic contribution are briefly discussed.