Magnetic structures of non-stoichiometric hexagonal RNi1−xIn1+x (R=Dy, Ho, Er) compounds

Abstract Results of neutron diffraction studies of DyNi 0.9 In 1.1 , HoNi 0.8 In 1.2 and ErNi 0.9 In 1.1 compounds crystallizing in the hexagonal ZrNiAl-type structure are reported. Previously published data for stoichiometric 1–1–1 compounds indicate that HoNiIn and ErNiIn compounds are ferromagnets (ordering along the c -axis) with T C of 22 and 9 K, respectively, while DyNiIn was found to be an antiferromagnet with T N of 32 K (J. Magn. Magn. Mater. 262 (2003) L177; J. Magn. Magn. Mater., in press). DC bulk magnetic measurements show that with the rise of the x parameter the ordering temperature is lowered; moreover changes in the magnetic ordering occur. At 1.5 K the HoNi 0.8 In 1.2 compound has a non-collinear magnetic structure, for the ErNi 0.9 In 1.1 compound an additional sine-modulated component lying in the basal plane was found. For the DyNi 0.9 In 1.1 compound the antiferromagnetic character of magnetic coupling is conserved, but some changes in comparison to 1–1–1 stoichiometry were noticed.