Ferromagnetism in the high-pressure phases of (GaSb)1−x Mnx

Electrotransport and magnetic properties of Cr–GaSb phases synthesized under high pressure

“…5) is almost order of magnitude higher than the values reported in Ref. [11] for the tetragonal phase MnGaSb. The elctrical resistance of the orthorhombic phase is a more complicated point because the bulk resistance of a pure phase can well be shunted by inclusions of metallic chromium.…”

“…It was found that the critical temperature T C =350 K remains almost constant and slightly depends on the initial chromium content. Note that the critical temperature is substantially higher than the one for MnGa 2 Sb 2 which varies in the range 210-310 K depending on the Mn content [10,11,12,13]. On the other hand, an increase in the chromium content up to x=0.8 leads to some smoothing and widening of the ferromagnetic transition as demonstrated in Fig.…”

“…[12] form a series of solid-solutions in the orthorhombic phase (previously this phase in Refs. [10,11,12] was erroneously identified as a simple cubic structure).…”

“…Earlier, the attempts were made to use high-pressure synthesis for producing spintronic materials. In the studies [10,11,12,13] high pressure was used to obtain a solution of manganese in GaSb which has a zinc-blend structure under normal conditions. It should be noted that manganese is a popular dopant in the production of spintronic materials because, unlike other magnetic atoms (Cr for example) it can much more easily form solid solutions in semiconductor lattices which leads to the formation of diluted magnetic semiconductors.…”

Magnetoresistance of the high-pressure ferromagnetic phases (GaSb)2M (M=Cr,Mn)

“…Interesting to note, that in the phase diagram of Cr-Si, for example, there is no thermodynamically stable phases with composition 1:4 [11], similar to the (GaSb) 2 M, so these compounds recovered from the high pressure are likely to be metastable at the ambient pressure. It was previously shown that both these phases (GaSb) 2 Mn and (GaSb) 2 Cr are ferromagnetic with T C ≈ 300 and 360 K respectively [3,4,5,2,6,7]. In the former case Curie temperature significantly depends on Mn content [4], so small deviation from stochiometry can lead to significant lowering of the critical temperature, the effect which is not observed in (GaSb) 2 Cr.…”