Around the composition Gd<sub>4</sub>Co<sub>3</sub>: Structural, magnetic and magnetocaloric properties of Gd<sub>6</sub>Co<sub>4.85(2)</sub>
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en
Article de revue
Ce document a été publié dans
Intermetallics. 2010, vol. 18, n° 6, p. 1216-1221
Elsevier
Résumé en anglais
Investigation of the Gd–Co system around the composition Gd<sub>4</sub>Co<sub>3</sub> showed that this compound does not exist. When samples with the nominal composition Gd<sub>4</sub>Co<sub>3</sub> are synthesized a mixture ...Lire la suite >
Investigation of the Gd–Co system around the composition Gd<sub>4</sub>Co<sub>3</sub> showed that this compound does not exist. When samples with the nominal composition Gd<sub>4</sub>Co<sub>3</sub> are synthesized a mixture of Gd<sub>12</sub>Co<sub>7</sub> and Gd<sub>6</sub>Co<sub>4.85(2)</sub> (=Gd<sub>4</sub>Co<sub>3.23(2)</sub>) is observed. Gd<sub>6</sub>Co<sub>4.85(2)</sub> is the only compound found around the composition Gd:Co = 4:3. Its structure was determined by means of X-ray diffraction on single crystal with the space group <i>P</i>6<sub>3</sub>/<i>m</i>. The cell parameters are <i>a</i> = 11.593(2) Å and <i>c</i> = 4.0495(14) Å. Its structure is closely related to the Ho<sub>4</sub>Co<sub>3.07</sub>-type or to the Ce<sub>6</sub>Ni<sub>1.67</sub>Si<sub>3</sub>-type structure. Gd<sub>6</sub>Co<sub>4.85(2)</sub> exhibits only one ferro(ferri)magnetic transition at 219(1) K and the second magnetic transition at 163 K, wrongly attributed to a spin reorientation, corresponds indeed to the ferromagnetic transition of the impurity Gd<sub>12</sub>Co<sub>7</sub>. Gd<sub>6</sub>Co<sub>4.85(2)</sub> presents magnetocaloric properties with a maximal adiabatic temperature change Δ<i>T</i><sub>ad</sub> equal to 4.4 K for <i>μ</i><sub>0</sub>Δ<i>H</i> = 4.5 T.< Réduire
Mots clés en anglais
Rare-earth intermetallics
Magnetic properties
Phase identification
Site occupancy
Energy systems
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