Portal de Periódicos da CAPES

Mössbauer study of antiferromagnetic CuFeO2

2008; Elsevier BV; Volume: 320; Issue: 20 Linguagem: Inglês

10.1016/j.jmmm.2008.04.018

1873-4766

Dong Hyeok Choi, In‐Bo Shim, Chul Sung Kim,

Magnetic Properties and Synthesis of Ferrites

We have studied the magnetic spin structure of antiferromagnetic CuFeO2 by X-ray diffraction (XRD) and Mössbauer spectroscopy. Its crystal structure determined by XRD analysis was a rhombohedral structure (space group R-3m) and lattice constants a0 and c0 were 3.0333 and 17.1595 Å, respectively. In spite of 4-Fe sublattices in a delafossite CuFeO2, its Mössbauer spectra were analyzed with 1-set (6-Lorentzian lines) below 10 K due to the collinear-commensurate spin structure, but the spectra were fitted with 4-sextet above 10 K due to the incommensurate spin structure. This phenomenon was attributed to the spin–lattice relaxation effect. Magnetic Néel temperature was also determined at 18 K, which corresponded to the high-spin Fe3+ valance state. On the other hand, CuFe0.98Al0.02O2 powder with a noncollinear spin structure was fitted with 4-sextet at 4.2 K.