Effect of hydrogen on the magnetic anisotropy and spin–reorientation transition in ErFe11Ti single crystal (original) (raw)

Magnetic and Mössbauer spectral study of ErFe[sub 11]Ti and ErFe[sub 11]TiH

Journal of Applied Physics, 2003

X-ray diffraction, isothermal magnetization at 5 and 300 K, ac magnetic susceptibility measurements between 5 and 200 K, and iron-57 Mössbauer spectral measurements between 4.2 and 295 K have been carried out on ErFe 11 Ti and ErFe 11 TiH. Hydrogen uptake has been measured by gravimetric analysis and the insertion of hydrogen into ErFe 11 Ti increases its magnetization, magnetic hyperfine fields, and isomer shifts as a result of the associated lattice expansion. Peaks and steplike changes in both the real and imaginary components of the ac magnetic susceptibility are observed at ϳ50 and 40 K for ErFe 11 Ti and ErFe 11 TiH, respectively, and are assigned to spin-reorientation transitions resulting from the temperature dependence of the sixth-order Stevens crystal-field term of erbium. The Mössbauer spectra have been analyzed with a model which considers both these spin reorientations and the distribution of titanium atoms in the near-neighbor environment of the three crystallographically distinct iron sites. The assignment and the temperature dependencies of the hyperfine fields and isomer shifts are in complete agreement with the Wigner-Seitz cell analysis of the three iron sites in ErFe 11 Ti and ErFe 11 TiH. The changes in the hyperfine field and isomer shift with the number of titanium near neighbors of the three iron sites are in agreement with the values observed for related titanium-iron intermetallic compounds.

Magnetic and Mössbauer spectral study of ErFe 11 Ti and ErFe 11 TiH

Hydrogen effects on the magnetic properties of RFe11Ti compounds

Journal of Alloys and Compounds, 1998

Hydrogen insertion in the RFe Ti series of alloys induces a marked change in the main structural and magnetic parameters. The unit 11 cell volume is found to increase significantly upon hydrogenation. The location of hydrogen atoms within the crystal structure is given according to neutron diffraction experiments performed on CeFe TiH. Magnetisation measurements have been performed on 11 magnetically aligned samples between 4 K and 300 K in field up to 240 kOe (24 T). These high field magnetisation measurements are presented for CeFe TiH, GdFe Ti, GdFe TiH and SmFe TiH. The room temperature saturation magnetisation is increased after 11 11 11 11 hydrogen uptake. A raise of the Curie temperature upon hydrogen insertion is also observed. Among the RFe Ti magnetic compounds, the SmFe Ti is a potential candidate for high performance permanent magnets.

High-Field Magnetization Measurements for a Single Crystal of Er2Fe17H3 Hydride

Journal of Low Temperature Physics, 2010

High-field magnetization process of the single crystal of Er 2 Fe 17 H 3 is investigated and compared with that of the parent Er 2 Fe 17 in order to clarify the effect of interstitial hydrogen on magnetic properties. Substantial change in the magnetic anisotropy behavior observed for Er 2 Fe 17 H 3 is explained by the modification of the interaction between the 4f -shell orbital moment of Er and the crystal field leading to the change of the second-order crystal electric field coefficient A 0 2 . Hydrogenation does not practically affect the intersublattice molecular field.

Spin reorientation and magnetization anomaly in Er2Fe14B and Tm2Fe14B

Solid State Communications, 1985

Static magnetic measurements have been carried out on single crystals of ErzFer4B and TmzFe,,B in a temperature range between 77 and 590K. Spin reorientation phenomena have been found in both compounds slightly above room temperature. In Er,Fer,B, the easy direction of magnetization changes from [loo] to [OOI] at 316 K as temperature increases, and TmzFer4B from [IOO] to [OOl] at 310K. Anomalously large anisotropy in the saturation magnetization has been detected around the spin reorientation temperature.

Structural and Magnetocaloric Properties of ErFe 2 . 4 Al 0 . 6 Compound

Journal of Superconductivity and Novel Magnetism, 2014

The structural and magnetic properties of the single-phase pseudobinary ErFe 2.4 Al 0.6 compound, obtained under arc-melting conditions, have been investigated. Single crystal X-ray diffraction analysis revealed that this compound is stabilized with a hexagonal CeNi 3-type structure (space group P6 3 /mmc). The partial substitution of Fe by Al in this compound occurring at all the metallic sites is reflected in the decrease of the Curie temperature Tc. Magnetization curves (2-450 K; 0-5 T) indicate a ferrimagnetic ordering with four magnetic phases induced by competitional interactions between magnetic moments of both Er and Fe. The magnetocaloric effect has been estimated from the magnetic isotherms. The relative cooling power (RCP) value indicates relatively promising magnetic refrigerant material.

High-field magnetic behavior and forced-ferromagnetic state in anErFe11TiHsingle crystal

Physical Review B, 2015

The crystal-field and exchange parameters are determined for the single-crystalline hydride ErFe 11 TiH compound by analyzing the experimental magnetization curves obtained in magnetic fields of up to 60 T. By using the calculated parameters we succeeded in modeling theoretical magnetization curves for ErFe 11 TiH up to 200 Т and to study in detail the transition from ferrimagnetic to a ferromagnetic state in the applied magnetic field.

Magnetic structure and magneto-volume anomalies in Er2Fe17 compound

Journal of Physics: …, 2011

Neutron powder diffraction shows that the intermetallic Er2Fe17 compound with hexagonal crystal structure has a ferrimagnetic ground state (TC = 303 K). At T = 5 K the magnetic moments of Fe sublattice (μ ~ 2 μB) are therefore antiparalell to those of the Er one (μ ~ 9 μB), all of them lying on the basal plane. This compound exhibits strong magneto-volume effects up to temperatures in the vicinity of TC. Neutron thermo-diffraction experiments also show an anomalous temperature dependence of the cell volume, including a negative thermal expansion coefficient below 300 K. In addition, a positive spontaneous volume magnetostriction is observed up to T ~ 400 K, with a maximum (ωS ~ 0.02) located at T = 5 K.

Influence of hydrogenation on the magnetic properties of Er2Ni2Al

Chemistry of Metals and Alloys, 2016

The magnetic properties of Er 2 Ni 2 Al and Er 2 Ni 2 AlH 5.3 have been studied in the temperature range 2-300 K. Er 2 Ni 2 Al is an antiferromagnet with T N = 5 K, as indicated by a pronounced maximum in the temperature dependence of the magnetic susceptibility in magnetic fields below 1 T. In the paramagnetic region, the susceptibility is described by the Curie-Weiss law, yielding an effective moment of 9.69 µ B /Er and θ p =-14 K. The field dependence of the magnetization in the ordered state exhibits a metamagnetic transition around 2 T with a relatively wide hysteresis. The hydride Er 2 Ni 2 AlH 5.3 does not show any magnetic ordering above T = 2 K. The Curie-Weiss law fit of the magnetic susceptibility curve yields the values 9.63 µ B /Er and θ p =-10 K. The magnetic behavior of both Er 2 Ni 2 Al and Er 2 Ni 2 AlH 5.3 is supported by the shape of the temperature dependence of the heat capacity curves. The upturn in C/T vs. T for Er 2 Ni 2 AlH 5.3 , which is suppressed by an applied magnetic field, is suggestive of magnetic ordering at still lower temperatures. The dramatic suppression of Er-Er exchange interactions (the size of the Er moments is generally stable) can be understood as a consequence of H bonding, which reduces the concentration of conduction electrons.

Effect of hydrogen on the magnetic anisotropy and spin–reorientation transition in ErFe11Ti single crystal (original) (raw)

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