On the origin of the giant isotopic effect of hydrogen on the magnetic properties of YFe2A4.2 (A = H, D): A high pressure study

Abstract

In order to identify the origin of the giant isotope effect observed on the magnetic properties of YFe 2 A 4.2 compounds (A ¼ H, D) and probe the role of the cell volume difference, we have compared the effect of hydrostatic pressure up to 1.0 GPa on the ferro-antiferromagnetic transition temperatures T F-AF and spontaneous magnetization of YFe 2 D 4.2 and YFe 2 H 4.2. Using compressibility value of 0.013 GPa À1 and the remarkably different negative pressure slopes of T F-AF , the existence of critical volume where the ferromagnetism is suppressed at 0 K, V C ¼ 501.7 6 0.3 A 3 , was demonstrated. This consequently established the crucial role of volume on the huge isotope effect observed on the magnetic properties. V

Metamagnetic transitions in Y0.5Er0.5Fe2D4.2 deuteride studied by high magnetic field and neutron diffraction experiments

“…According to previous studies on YFe2D4.2 (x=0) this transition is related to the IEM behavior of the Fe sublattice. In these previous works [9,16], the AFM structure has been described as the alternance of two ferromagnetic layers with Fe moments perpendicular to the monoclinic b axis and in opposite direction to each other, separated by a row of non-magnetic [21,22]. Different dTM0/dV slopes were obtained for the deuteride and the hydride, but they converged towards a critical volume VC= 501.7 Å 3 , below which the ferromagnetic ground state was suppressed.…”

Electronic specific heat coefficient and magnetic properties of Y(Fe1−xCox)2 Laves phases: A combined experimental and first

“…−1 for YFe 2 , reaches a broad maximum for intermediate concentrations, and drops sharply to zero near the critical Co concentration [11]. The pseudo-binary Laves phases Y(Fe 1−x Co x ) 2 exhibit both extraordinary magnetic properties [7,[12][13][14][15] and ability to absorb hydrogen [16][17][18][19]. Moreover, the DyFe 2 /YFe 2 magnetic thin films are reversible exchange-spring magnets [20,21] and the YCo 2 alloys with rare-earth elements R 1−x Y x Co 2 (R = Er, Gd) are considered as magnetocaloric materials for application in magnetic refrigerators [22,23].…”

Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe2 compounds

“…4 In addition, a large change of magnetic properties under applied pressure has been observed for YFe 2 hydrides (deuterides) and consequently a change of the magnetocaloric properties. 5,6 Here, we will focus our attention on the IEM of Fe in a selected Laves phase. The effect of hydrostatic pressure is important for fundamental study of magnetic properties and their correlation with electronic structure.…”