MAGNETIC-PROPERTIES AND SN-119 HYPERFINE INTERACTIONS INVESTIGATED INRCOSN (R=TB, DY, HO, ER) COMPOUNDS

It was confirmed that samples of RCoSn (R = Tb, Dy, Ho, and Er) compou nds have the orthorhombic NiTiSi-type structure. They all order antife rromagnetically with transition temperatures T-N decreasing along the series: 20.5 K, 10 K, 7.8 K, and 4 K, respectively. Their complex non- collinear magnetic structures result in a multicomponent appearance of the Mossbauer spectra recorded for 23.8 keV gamma-transition of Sn-11 9 at temperatures below T-N. In the case of DyCoSn the hyperfine-split spectra are observed above T-N due to the non-vanishing transferred f ields at the tin sites in the paramagnetic state. A change in the type of magnetic ordering of TbCoSn at 11.6 K may be inferred from both ma gnetic and Mossbauer measurements. Mean values of the saturation trans ferred hyperfine fields at tin nuclei scale roughly with the square ro ot of magnetic transition temperatures T-N.