Characterization of the quenched GaSb–MnSb composites with high fraction of the ferromagnetic component

In this work, we studied properties of the GaSb–MnSb composite (30 mol.% GaSb ＋ 70 mol.% MnSb), synthesized from a melt of elemental precursors and subjected to the post-growth quenching procedure. We used a combination of experimental methods to specify phase composition of studied systems and elemental composition of each phase. Presented results suggest that studied composites can be considered as an ensemble of large ferromagnetic MnSb inclusions (with sizes of order of 10 μm) embedded in GaSb matrix with small amount of diluted Mn atoms in it. We show that magnetic and magnetooptical properties of composites are primarily defined by the MnSb phase. However, transport and magnetotransport properties of GaSb-MnSb samples depends on both components. In general, low temperature magnetotransport is dominated by the contribution of the GaSb matrix, while at room temperature measured data are qualitatively similar to those for pristine MnSb polycrystals. Additive character of these contributions along with the absence of any magnetooptical response besides that characteristic for bulk MnSb polycrystals suggests that these composites do not contain any considerable fraction of nm-sized ferromagnetic inclusions. Nevertheless, our results suggests that bulk GaSb–MnSb nanocomposite can be obtained, e.g. by more aggressive quenching.