Isotope effect on the thermodynamic and structural properties of Y1−yRyFe2(H,D)x(γ) compounds (R=Tb, Er, Lu; 4.0≤x(γ)≤4.5)

Journal of Magnetism and Magnetic Materials

Isnard

Guillot

et al. 2019

Self Cite

The structural and magnetic properties of Y0.5Er0.5Fe2D4.2 deuteride have been investigated by continuous high field magnetic measurements up to 35 T and neutron powder diffraction experiments versus temperature and applied field. Y0.5Er0.5Fe2D4.2 crystallizes in a monoclinic structure (Pc space group) resulting from the deuterium order into 18 interstitial tetrahedral sites. At low field, the deuteride is ferrimagnetic (Ferri) up to 38 K, between 38 and 50 K, it undergoes a first order transition towards an antiferromagnetic (AFM) structure, which remains present up to TN=115 K. Upon applied field, two different types of metamagnetic behavior are observed depending on the temperature range. Below 38 K, a forced ferrimagneticferromagnetic (FM) transition is observed at a transition field BTrans of only 7 T (at 2 K), which is among the smallest encountered for Fe rich intermetallics. BTrans is not very sensitive to temperature changes nor to the Er content and its moderate value is explained by a deuterium induced weakening of the Er-Fe interaction. The second metamagnetic transition, observed between 38 and 150 K, from an AFM (Para) towards a FM structure, is related to the itinerant electron metamagnetic behavior of the Fe sublattice. BTrans increases linearly versus temperature with a dB/dT slope of 0.24±0.01 T.K-1. Above BTrans, Er moments parallel to the Fe moments are induced.

Section: Experimental Methodsmentioning

confidence: 99%

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

Journal of Magnetism and Magnetic Materials

Isnard

Guillot

et al. 2019

Self Cite

“…25,34 We observed the cell volume of the monoclinic Y 0.5 Tb 0.5 Fe 2 D 4.2 to be intermediate between that of YFe 2 D 4.2 and YFe 2 H 4.2 , due to the relatively larger atomic radius of Tb compared with Y in the deuteride as explained in Ref. 35. Results have shown ͑Fig.…”

Section: Resultsmentioning

confidence: 65%

Investigation of compounds for magnetocaloric applications: YFe2H4.2, YFe2D4.2, and Y0.5Tb0.5Fe2D4.2

Journal of Applied Physics

Mazet

2009

Self Cite

International audienceThe magnetocaloric properties of powder samples of the monoclinic YFe2H4.2, YFe2D4.2, and Y0.5Tb0.5Fe2D4.2 compounds have been studied at their itinerant electron metamagnetic transition (TM0 = 131, 84, and 127 K, respectively). Large reversible entropy changes are observed, up to −ΔSM = 10.83 J K−1 kg−1 for a field variation of 5 T in YFe2D4.2, making these alloys candidates for magnetic refrigeration applications. The results are compared with previously published data on other potential magnetic refrigerants with itinerant electron metamagnetic transitions

“…The synthesis of the Y1-xErxFe2 intermetallic compounds (x = 0, 0.1, 0.3, 0.5, 0.7 and 1) and their corresponding hydrides and deuterides is described in details in refs [64,72]. The intermetallics were prepared by induction melting and annealed 4 weeks at 1073 K. The hydrides and deuterides were prepared by solid-gas reaction using a Sieverts apparatus.…”

Section: Methodsmentioning

confidence: 99%

“…Another way to tune the cell volume of YFe2H(D)4.2 compounds is to substitute Y by another R element like Gd, Tb, Er or Lu as reported in [64]. The structural and magnetic properties of pseudobinary Y1-xErxFe2D4.2 compounds (x = 0.3 and 0.5) have been already studied by combining high magnetic field and neutron diffraction experiments [65][66][67].…”

Section: Introductionmentioning

confidence: 99%

Origin of the metamagnetic transitions in Y1−Er Fe2(H,D)4.2 compounds

Journal of Magnetism and Magnetic Materials

Isnard

Shtender

et al. 2020

Self Cite

The structural and magnetic properties of Y1-xErxFe2 intermetallic compounds and their hydrides and deuterides Y1-xErxFe2H(D)4.2 have been investigated using X-ray diffraction and magnetic measurements under static and pulsed magnetic field up to 60 T. The intermetallics crystallize in the C15 cubic structure (Fd-3m space group), whereas corresponding hydrides and deuterides crystallize in a monoclinic structure (Pc space group). All compounds display a linear decrease of the unit cell volume versus Er concentration; the hydrides have a 0.8% larger cell volume compared to the deuterides with same Er content. They are ferrimagnetic at low field and temperature with a compensation point at x = 0.33 for the intermetallics and x = 0.57 for the hydrides and deuterides. A sharp first order ferromagnetic-antiferromagnetic (FM-AFM) transition is observed upon heating at TFM-AFM for both hydrides and deuterides. These compounds show two different types of field induced transitions, which have different physical origin. At low temperature (T < 50 K), a forced ferri-ferromagnetic metamagnetic transition with Btrans1  8 T, related to the change of the Er moments orientation from antiparallel to parallel Fe moment, is observed. Btrans1 is not sensitive to Er concentration, temperature and isotope effect. A second metamagnetic transition resulting from antiferromagnetic to ferrimagnetic state is also observed. The transition field Btrans2 increases linearly versus temperature and relates to the itinerant electron metamagnetic behavior of the Fe sublattice. An onset temperature TM0 is obtained by extrapolating TFM-AFM (B) at zero field. TM0 decreases linearly versus the Er content and is 45±5 K higher for the hydrides compared to the corresponding deuteride. The evolution of TM0 versus cell volume shows that it cannot be attributed exclusively to a pure volume effect and that electronic effects should also be considered.