FE-57 MOSSBAUER STUDIES OF YFE11TI(T=77-550-K)

57Fe Mossbauer effects of YFe11Ti with the ThMn 12 structure have been studied in a temperature range of 77-550 K. This material may be considered as the prototype of similar systems with yttrium replaced by a magnetic rare earth. The results show that the largest hyperfine field is on the 8i site and the smallest on the 8f site. The hyperfine fields are 23.5 T, 21.8 T and 20.2 T, the quadrupole splittings are 0.32, -0.17 and 0.27 mm s-1 and the spectrum shifts are 0.01, -0.40 and -0.11 mm s-1 for the 8i, 8j and 8f sites at room temperature. The quadrupole splittings are 0.29, 0.51 and 0.63 mm s-1 and the spectrum shifts are -0.27, -0.48 and -0.31 mm s-1 from the paramagnetic spectrum at a temperature of 550 K. Almost all Ti atoms occupy the 8i site according to the subspectral area ratios of 2.9:4.2:3.9 for the 8i, 8j and 8f sites. With increasing temperatures, HHF(T)/HHF(77 K) decreases the most slowly for the 8j site and the most rapidly for the 8f site.