Magnetic properties and surface morphology of the intermetallic compound Dy$_{2}$Fe$_{10}$Al$_{7}$ and its hydride

Influence of hydrogenation on the microstructural parameters, surface topology, and temperatures of magnetic phase transitions in Dy$_{2}$Fe$_{10}$Al$_{7}$ was studied. Thermomagnetic properties in the obtained hydride Dy$_{2}$Fe$_{10}$Al$_{7}$H$_{3.2}$ were also investigated. Hydrogenation was found not to change the Curie point of the compound Dy$_{2}$Fe$_{10}$Al$_{7}$, but at the same time it affects remarkably the temperature of the magnetic compensation transition. The coercive force increases upon hydrogenation, and thus the magnetocrystalline anisotropy can be concluded to increase due to changes in the local environment of the dysprosium ion caused by insertion of hydrogen atoms into the crystal lattice. The relative volume change $\Delta V/V$ of the unit cell of the hydride Dy$_{2}$Fe$_{10}$Al$_{7}$H$_{3.2}$ was shown to be 3%. The investigation of the peculiarities of the structural state allowed concluding that hydrogenation causes significant modification of the microstructure, which in turn changes the physical and functional properties of the hydrogenated materials.