Crystal structure and magnetic properties were studied on a single crystal of HoFe6Al6H and compared with those of the parent HoFe6Al6compound with a tetragonal crystal structure of the ThMn12 type. Hydrogenation leads to a 1% volume expansion. HoFe6Al6is a ferrimagnet with exact compensation of the Ho and Fe sublattices magnetizations at low temperatures. Both the hydride and the parent com-pound display a high magnetic anisotropy of the easy-plane type, a noticeable anisotropy exists also within the easy plane with the [110] axis as the easy magnetization direction. The hydrogenation in-creases slightly (from 10 to 10.45mB) the magnetic moment of the Fe sublattice as a result of volume expansion. It leads to a decompensation of the Fe and Ho sublattices and HoFe6Al6H has a spontaneous moment 0.45mB/f.u. The enhancement of the FeeFe intra-sublattice exchange interaction results in a higher Curie temperature (TC) value, 350 K in the hydride as compared to 315 K of HoFe6Al6. The HoeFe inter-sublattice interaction is also enhanced in the hydride. The molecular fieldHmolcreated on Ho ions by Fe sublattice is 38 T in HoFe6Al6and 48 T in HoFe6Al6H. The inter-sublattice exchange constantnHoFeis 3.8 T/mBand 4.6 T/mB, respectively. High-field measurements confirm the enhancement of the HoeFe exchange interaction in the hydride found from the temperature dependence of magnetization

http://repository.vnu.edu.vn/handle/VNU_123/58189



Crystal structure and magnetic properties were studied on a single crystal of HoFe6Al6H and compared with those of the parent HoFe6Al6compound with a tetragonal crystal structure of the ThMn12 type. Hydrogenation leads to a 1% volume expansion. HoFe6Al6is a ferrimagnet with exact compensation of the Ho and Fe sublattices magnetizations at low temperatures. Both the hydride and the parent com-pound display a high magnetic anisotropy of the easy-plane type, a noticeable anisotropy exists also within the easy plane with the [110] axis as the easy magnetization direction. The hydrogenation in-creases slightly (from 10 to 10.45mB) the magnetic moment of the Fe sublattice as a result of volume expansion. It leads to a decompensation of the Fe and Ho sublattices and HoFe6Al6H has a spontaneous moment 0.45mB/f.u. The enhancement of the FeeFe intra-sublattice exchange interaction results in a higher Curie temperature (TC) value, 350 K in the hydride as compared to 315 K of HoFe6Al6. The HoeFe inter-sublattice interaction is also enhanced in the hydride. The molecular fieldHmolcreated on Ho ions by Fe sublattice is 38 T in HoFe6Al6and 48 T in HoFe6Al6H. The inter-sublattice exchange constantnHoFeis 3.8 T/mBand 4.6 T/mB, respectively. High-field measurements confirm the enhancement of the HoeFe exchange interaction in the hydride found from the temperature dependence of magnetization

http://repository.vnu.edu.vn/handle/VNU_123/58189