Hardness and Oxidation Resistance, Magnetic Properties of REB48Si2 ($\text{RE} = \text{Y}$, Tb, Dy, Ho, Er, Lu) Compounds Obtained by Arc Melting

概要

論文の詳細を見る
We report the synthesis of REB48Si2 ($\text{RE} = \text{Y}$, Tb, Dy, Ho, Er, Lu) compounds by arc melting. The diffraction patterns of REB48Si2 ($\text{RE} = \text{Y}$, Tb, Dy, Ho, Er, Lu) compounds showed a good match to those determined with a YB50-type structure. The lattice constants of REB48Si2 ($\text{RE} = \text{Y}$, Tb, Dy, Ho, Er, Lu) are in the ranges of $a=1.652--1.702$ nm, $b=1.748--1.779$ nm, and $c=0.918--0.961$ nm. The lattice constants of these compounds are consistent with that reported for the reference TbB41Si1.2 compound. The compounds had chemical compositions of $[\text{Si}]/[\text{Y}] = 1.08$, $[\text{Si}]/[\text{Dy}] = 1.02$, $[\text{Si}]/[\text{Tb}, \text{Lu}] = 0.89$, $[\text{Si}]/[\text{Ho}] = 0.82$, and $[\text{Si}]/[\text{Er}] = 0.70$. The silicon-to-rare earth composition ratios are comparable to reference values. The values of the micro-Vickers hardness of REB48Si2 for Y, Tb, Dy, Ho, Er, and Lu are $21.8 \pm 0.9$, $17.8 \pm 0.4$, $16.3 \pm 0.8$, $16.5 \pm 0.7$, $16.3 \pm 0.4$, and $16.6 \pm 0.7$ GPa, respectively. When the atomic radius of the rare earth element becomes large, hardness shows a tendency of becoming high. The oxidation beginning temperature of our compounds showed a dependence on the melting point of the rare earth element. Thermo-gravimetric analysis was carried out to study REB48Si2 compounds. $\text{REB$_{50}$-type} + \text{B$_{2}$O$_{3}$} + \text{SiO$_{2}$}$ are identified as oxidized products for all samples. The magnetic transition temperature for our TbB48Si2 sample appears to slightly below 15 K.
2007-12-15

Hardness and Oxidation Resistance, Magnetic Properties of REB48Si2 ($\text{RE} = \text{Y}$, Tb, Dy, Ho, Er, Lu) Compounds Obtained by Arc Melting

スポンサーリンク

概要

著者

関連論文

スポンサーリンク