MOSSBAUER AND CRYSTAL-STRUCTURE STUDY OF YSR2CU2FEOY ISOMORPHIC WITH YBA2(CU1-XFEX)3OY

Mossbauer spectroscopy, magnetic susceptibility, and Rietveld analysis were used to study the magnetic and structural properties of YSr2Cu2FeOy prepared under different annealing conditions. The structure was refined using the tetragonal space group P4/mmm for both the O2 and the Ar postannealed samples. Mossbauer analysis shows that Fe is equally distributed between the Cu(1) and Cu(2) sites. The hyperfine parameters of Fe in the Cu(2) site are typical of Fe3+ in the high-spin state (S = 5/2) for both samples. The magnetic properties of the system depend strongly on the annealing atmosphere. The O2 postannealed sample exhibits antiferromagnetic order with T(N) = 60 K, whereas for the Ar postannealed sample T(N) = 445 K.