Effect of Tb/Gd Substitution on Crystal Structure and Exchange Interactions of Gd1 - xTbxNi3 Intermetallic Compounds
A. Chrobak, A. Bajorek and G. Chełkowska
A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
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In the paper an influence of Tb/Gd substitution on crystal structure and exchange interactions of Gd1 - xTbxNi3 (x = 0.0, 0.5, 0.8, 1.0) polycrystalline compounds have been studied. The crystal structure of all samples was checked at the room temperature by means of X-ray diffraction. Exchange integrals of R-R (JRR), T-T (JTT) and R-T (JRT) atoms were evaluated from M(T) magnetization curves (2-300 K, 2 T) based on the mean field theory calculation. As it was shown the samples examined are single phase and crystallize in the PuNi3 (space group R-3m) type of crystal structure. The Tb/Gd substitution causes the decrease of lattice parameters as well as the volume of the unit cell. With increase of the x parameter the magnetic moment of Tb atoms increases from 6.94 μB (x = 0.5) to 8.12 μB (x = 1). The M(T) dependence of the examined compounds depends almost 8 times stronger on exchange interactions within the R-R site than the interactions between the two antiferromagnetically coupled magnetic sublattices R-T.
DOI: 10.12693/APhysPolA.121.1132
PACS numbers: 75.50.Gg, 75.30.Et, 71.20.Lp