Pressure induced anisotropic magnetovolume phenomena in Lu₂Fe₁₇Intermetallics

Magnetic properties of Lu2Fe16X (X = Fe, Ni, Cr, Si) intermetallics under high hydrostatic pressure

“…Thus, this significant increase of the ordering temperature cannot be explained by a magnetovolume effect. A substantial decrease of T C under pressure in Lu 2 Fe 16 Ni and Lu 2 Fe 16 Cr is of the same magnitude as the pressure decrease of the Néel temperature T N of Lu 2 Fe 17 in pressure range below P C [6], see Table 1. Moreover, this pressure effect is also well comparable with an effect of hydrogenation.…”

“…Moreover, this pressure effect is also well comparable with an effect of hydrogenation. Taking into account a pronounced anisotropy in changes of lattice parameters induced by pressure (|dc/dP| |da/dP|) in Lu 2 Fe 17 [6] and by hydrogenation (da/dx dc/dx) in Lu 2 Fe 17 H x [9], we have received the unique value of the Grüneissen parameter Γ = dln T C /dln V = 12.5 ± 0.5 on the assumption that dln V = 3 × dln a. The magnetoelastic phenomena in a vicinity of the ordering temperatures T C and T N of Lu 2 Fe 16 X intermetallics reflect mainly changes of the exchange interactions in the basal planes that are induced by a variation of the lattice a-parameter.…”

“…Recently, the ferromagnetic state of Lu 2 Fe 17 was totally suppressed and the antiferromagnetic helical structure was stabilized down to the lowest temperatures under external hydrostatic pressure. The critical pressure P C is relatively low, P C = 0.35 GPa [4][5][6]. The metamagnetic transition from the helical back to the ferromagnetic structure can be induced in Lu 2 Fe 17 by an external magnetic field applied in the basal crystal plane.…”

Magnetism of a Lu2Fe17H Single Crystal under Pressure

“…9) Therefore, we can estimate the effect of chemical pressure due to hydrogenation as dlnM/dp = -0.11 GPa -1 at 5 K. Under action of the hydrostatic pressure on Lu 2 Fe 17 , the magnetic moment decreases with dlnM/dp = -0.14 GPa -1 . 5) Close values of the effect may imply an equivalency of the chemical and external pressures. However, effects on the ordering temperature are quite different (see below).…”

“…1,2) A significant change of magnetic properties of Lu 2 Fe 17 is observed under hydrostatic pressure [3][4][5] as well as due to interstitial solution of atoms of light elements. 6,7) In this paper we studied changes in magnetic properties due to the lattice expansion of Lu 2 Fe 17 produced by the hydrogenation up to Lu 2 Fe 17 H composition and due to successive shrinkage of the lattice by application of external pressure.…”