Abstract
Using the experimental capability of the x-ray diffraction instrument available at the 25-T Florida split coil magnet at the NHMFL, we investigated the magnetostriction of polycrystalline . The magnetostriction was measured in the vicinity of the ferromagnetic transition with , at 250, 290, and 300 K. exhibits an anisotropic change in lattice parameters as a function of magnetic field near the Curie temperature, and a monotonic variation as a function of applied field has been observed, i.e., the axis increases significantly while the and axes decrease with increasing field in the vicinity of , irrespective of the measurement temperature. The volume magnetostriction decreases with decreasing temperature and changes its sign across . Density functional theory calculations for the nonpolarized and spin-polarized (ferromagnetic) models confirm that the observed changes in lattice parameters due to spin polarization are consistent with the experiment. The relationships for magnetostriction are estimated based on a simplified Landau model that agrees well with the experimental results.
- Received 30 July 2020
- Accepted 25 May 2021
DOI:https://doi.org/10.1103/PhysRevMaterials.5.064409
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