Investigation of the magnetic structure of TbxHo1-x

Three compositions of the binary alloy TbxHo1-x (x=0,45; 0,85; 0,96) have been investigated by the neutron diffraction method. The crystal structure of the samples is determined as Mg(hP2) type, hexagonally close packed. The neutron diffraction experiments have been carried out with polycristalline samples and a monochromatic neutron beam of λ = 0,1324 nm. It is found that the magnetic structure in the antiferromagnetic state is a simple spiral with magnetic moments located in the base plane. The angle of the spiral is determined for each of the investigated samples and is seen to vary linearly with the change of temperature. At temperatures lower than Tc the alloys pass into a ferromagnetic state and the magnetic moments grow with the temperature decrease, remaining in the base plane. The observed character of the magnetic structure of TbxH01-x is quite similar to that of pure Tb and no contribution from other types of spirals has been found