The influence of small hydrogen addition on the structural and magnetocaloric properties of high-purity nanocrystalline terbium
Abstrakt
Hydrogen absorption often induces changes of various properties of rare-earth metals. In this paper, we study the influence of hydrogenation on the structural, magnetic and magnetocaloric properties of high-purity nanocrystalline terbium.
Strong (00l) texture present in the parent Tb sample is practically destroyed after the hydrogenation procedure. We observe formation of agglomerates of different sizes and shapes depending on the hydrogen content in the samples.
We find traces of b-hydride (TbH2) in the main alpha-hydride TbHx phase. For TbHx with x = 0.25 and 0.5 at.H/f.u.
The effect of hydrogenation on the magnetocaloric properties is studied in magnetic fields up to 9 T. The magnetocaloric effect decreases after hydrogenation.
The -Delta S-M(T) curves feature a table-like effect in the vicinity of the magnetic phase transitions in magnetic fields exceeding 1 T. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd.
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