Structural and magnetic properties of R<sub>2</sub>Fe<sub>17-x</sub>Be<sub>x</sub> compounds with R = Y, Pr, Nd, Sm, Gd, Tb and Dy
R C Mohanty; C Zhang; S A Shaheen; A Murugaiah; A Raman; C G Grenier; R E Ferrell Jr
Журнал:
Journal of Physics: Condensed Matter
Дата:
2000-11-20
Аннотация:
The effect of partial Fe substitution by Be on structure and magnetic properties has been studied across the R<sub>2</sub>Fe<sub>17-x</sub>Be<sub>x</sub> series, where R = Y, Pr, Nd, Sm, Gd, Tb and Dy. On Be substitution, the Th<sub>2</sub>Zn<sub>17</sub> type rhombohedral structure is stabilized across the series, even for R = Dy and Tb which stabilize in the Th<sub>2</sub>Ni<sub>17</sub> type hexagonal structure without Be substitution. Depending on the R element, one or more Be atoms (up to five) per formula unit can be retained in the Th<sub>2</sub>Zn<sub>17</sub> type structure. The lattice parameters, magnetic ordering temperature and saturation magnetic moment decrease upon Be substitution. The easy magnetization direction of the samples with a higher magnetic ordering temperature is still within the basal c plane. The variation of magnetic properties is discussed in correlation with volume effects, dilution effects and electron hybridization.
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