Powder neutron diffraction studies of the crystallographic and magnetic structure of Ho2Fe9Ga8and Ho2Fe9Ga6Al2

The crystallographic and magnetic structures of Ho2Fe9Ga8 and Ho2Fe9Ga6Al2 were studied by powder neutron diffraction at room temperature. The atom fractional occupancies of Ga and Al and the magnetic moments of Ho and Fe were obtained by using Rietveld analysis program. The magnetic structures of the two samples show an easy-axis anisotropy, with the Fe magnetic moment being ferrimagneticlly coupled to those of Ho.