Above-room-temperature ferromagnetism in GaSb/Mn digital alloys

Abstract

Digital alloys of GaSb/Mn have been fabricated by molecular-beam epitaxy. Transmission electron micrographs showed good crystal quality with individual Mn-containing layers well resolved, no evidence of three-dimensional MnSb precipitates was seen in as-grown samples. All samples studied exhibited ferromagnetism with temperature-dependent hysteresis loops in the magnetization accompanied by metallic p-type conductivity with a strong anomalous Hall effect (AHE) up to 400 K (limited by the experimental setup). The anomalous Hall effect shows hysteresis loops at low temperatures and above room temperature very similar to those seen in the magnetization. The strong AHE with hysteresis indicates that the holes interact with the Mn spins above room temperature. All samples are metallic, which is important for spintronics applications.

How to make semiconductors ferromagnetic: a first course on spintronics

“…GaMnP, 7 GaMnN, 8 GeMn, 9 GaMnSb. 10 It is at present unclear whether all these reports of ferromagnetism (particularly at room temperatures or above) are indeed intrinsic magnetic behavior or are arising from clustering and segregation effects associated with various Mn-complexes (which have low solubility) and related materials problems. The observed ferromagnetism of GaMnAs is, however, well-established and is universally believed to be an intrinsic diluted magnetic semiconductor (DMS) phenomenon.…”

Ga1−xMnxSb grown on GaSb substrate by liquid phase epitaxy

“…The samples have been cleaved and stained with basic K 3 Fe(CN) 6 for epitaxial layer thickness measurements. The layer thickness d was about 2 mm.…”

“…Because the equilibrium solubility of Mn in GaSb can be as high as 15% [3], Ga 1Àx Mn x Sb could be grown with liquid phase epitaxy (LPE). Curie temperature T c is an important parameter for DMSs, and Ga 1Àx Mn x Sb is an interesting candidate for improving T c : with the higher-equilibrium solubility of Mn [4][5][6].…”

Search for stable ferromagnets amongAIV/Fe digital alloys (AIV=Si, Ge) using first-principles calculations

“…15 However, the nature of this FM ordering remains unclear. Complex atomic structure of real DAs, close to amorphous, 15 with smeared TM layers, 6,16 clusters, and secondary phases, 3 hinders direct comparison with ab initio calculations. From the theoretical side, however, even the simple model of atomically flat TM monolayers (MLs) can be very useful.…”

“…[1][2][3][4][5][6] A DA is an example of δ doping, [7][8][9] which represents a periodic sequence of the ultrathin TM layers embedded within a semiconductor host. Such a way of preparation allows tailoring the magnetic properties of the samples freely by changing the TM atoms' concentration or semiconductor spacer thickness and can yield to high Curie temperature.…”