A magnetic and Mössbauer spectral study of HoFe11Ti and HoFe11TiH

A magnetic and Mössbauer spectral study of PrFe11Ti and PrFe11TiH

“…These observed decreases in the hyperfine fields upon the replacement of one iron by one titanium near neighbor are very similar to those observed in the other RFe 11 Ti compounds and their hydrides [11][12][13][14][15]19], and are within the range of −1.1 to −6 T observed in a spinel oxide [20] and in Nd 2 Fe 16 Ti, respectively, [21].…”

“…In agreement with the Wigner-Seitz cell analysis [16] of the three inequivalent iron sites, the sequence of decreasing isomer shifts, 8i > 8j > 8f , follows the sequence of Wigner-Seitz cell volumes. A similar correlation between the isomer shifts and the Wigner-Seitz cell volumes has been observed in many RFe 11 Ti, R 6 Fe 13 X, and R 2 Fe 17 compounds [11][12][13][14][15]19,[24][25][26].…”

“…The average hyperfine field in PrFe 11 Ti increases upon hydrogenation, although the increase results only from increases of ∼0.5 T in the 8j and 8f hyperfine fields. This small increase in hyperfine field as compared to the increases observed in other RFe 11 TiH x compounds [11][12][13][14][15]19] may result from the small increase in unit-cell volume and consequently a small increase in the iron-iron near-neighbor distances.…”

“…Further, the model assumes a linear dependence of the hyperfine parameters upon the number of titanium nearest neighbors. The same model has been described in detail and successfully applied in the analysis of the Mössbauer spectra of several different RFe 11 TiH x compounds [11][12][13][14][15].…”

“…For each site these sextets represent iron atoms with zero, one, and two or more titanium near neighbors, respectively. A further subdivision of these nine spectral components is necessary when the compound exhibits planar magnetic behavior [11,[13][14][15]. For PrFe 11 Ti and PrFe 11 TiH the best fit of the Mössbauer spectra is achieved when we assume that the magnetization lies along the [1 0 0] direction.…”