Hydrogenation, crystal structure and magnetic properties of La（Fe0.91Si0.09）13H（D）y have been studied by pressure-composition isotherms （PCI）, X-ray diffraction （XRD）, differential scanning calorimetry （DSC）...Hydrogenation, crystal structure and magnetic properties of La（Fe0.91Si0.09）13H（D）y have been studied by pressure-composition isotherms （PCI）, X-ray diffraction （XRD）, differential scanning calorimetry （DSC） and magnetization measurements. The maximum absorption capacity is found to be 1.9 H（D） atoms per formula unit as a solid solution. All hydrides and deuterides crystallize in the NaZnl3-type cubic structure with the lattice parameter increasing linearly with H（D） concentration. The H（D） absorption enhances the Curie temperature significantly. The magnetic entropy change of the highly H-absorbed compound La（Feo.91Sio.09）13H1.81 reaches -26 J/kg-K under a magnetic field change of 5 T near the Curie temperature Tc =350 K. No observable isotope effect seems to imply that only the magnetovolume effect is responsible for the strong interplay between magnetism and lattice.展开更多
基金Project supported by the National Basic Research Program of China (973 Program) (Grant No. 2010CB833102)the Knowledge Innovation Project of the Chinese Academy of Sciencesthe National Natural Science Foundation of China (Grant Nos. 10974244 and 11004204)
文摘Hydrogenation, crystal structure and magnetic properties of La（Fe0.91Si0.09）13H（D）y have been studied by pressure-composition isotherms （PCI）, X-ray diffraction （XRD）, differential scanning calorimetry （DSC） and magnetization measurements. The maximum absorption capacity is found to be 1.9 H（D） atoms per formula unit as a solid solution. All hydrides and deuterides crystallize in the NaZnl3-type cubic structure with the lattice parameter increasing linearly with H（D） concentration. The H（D） absorption enhances the Curie temperature significantly. The magnetic entropy change of the highly H-absorbed compound La（Feo.91Sio.09）13H1.81 reaches -26 J/kg-K under a magnetic field change of 5 T near the Curie temperature Tc =350 K. No observable isotope effect seems to imply that only the magnetovolume effect is responsible for the strong interplay between magnetism and lattice.
