Mn doped InSb studied at the atomic scale by cross-sectional scanning tunneling microscopy

Abstract

We present an atomically resolved study of metal-organic vapor epitaxy grown Mn doped InSb that is ferromagnetic at room-temperature. Both topographic and spectroscopic measurements have been performed by cross-sectional scanning tunneling microscopy. The measurements show a perfect crystal structure without any precipitates and reveal that Mn acts as a shallow acceptor. The Mn concentration obtained from the cross-sectional STM data compares well with the intended doping concentration. No second phase material or (nano)clustering of the Mn was observed. While the pair correlation function of the Mn atoms showed that their local distribution is uncorrelated beyond the STM resolution for observing individual dopants, disorder in the Mn ion location is clearly noted. We discuss the implications of the observed disorder for a number of suggested explanations of the room-temperature ferromagnetism in Mn doped InSb grown by metal-organic vapor epitaxy.

Magnetism and Mn Clustering in (In,Mn)Sb Magnetic Semiconductors

“…22 No further evidence of secondary phase formation is observed by X-STM or high-resolution TEM for In 0.98 Mn 0.02 Sb layer. 21,22 However, for (In,Mn)Sb with a higher Mn concentration of 0.035, two magnetic phases are observed by X-ray magnetic circular dichroism (XMCD), which was 4 attributed to random and correlated substitution of Mn, respectively. 23 In contrast, for (In,Mn)Sb films grown on GaAs substrate with a Mn concentration higher than 0.1, hexagonal MnSb and MnAsSb precipitates are observed by TEM.…”

“…In previous work, we have synthesized single phase (In,Mn)Sb epitaxial films with a T c exceeding 400 K by metal–organic vapor phase epitaxy (MOVPE) . Cross-sectional scanning tunneling microscopy (X-STM) measurements reveal that Mn acts as a shallow acceptor in (In,Mn)Sb films at low Mn concentration . No further evidence of secondary phase formation is observed by X-STM or high-resolution TEM for In 0.98 Mn 0.02 Sb layer. , However, for (In,Mn)Sb with a higher Mn concentration of 0.035, two magnetic phases are observed by X-ray magnetic circular dichroism (XMCD), which was attributed to random and correlated substitution of Mn, respectively .…”

“…Cross-sectional scanning tunneling microscopy (X-STM) measurements reveal that Mn acts as a shallow acceptor in (In,Mn)Sb films at low Mn concentration . No further evidence of secondary phase formation is observed by X-STM or high-resolution TEM for In 0.98 Mn 0.02 Sb layer. , However, for (In,Mn)Sb with a higher Mn concentration of 0.035, two magnetic phases are observed by X-ray magnetic circular dichroism (XMCD), which was attributed to random and correlated substitution of Mn, respectively . In contrast, for (In,Mn)Sb films grown on GaAs substrate with a Mn concentration higher than 0.1, hexagonal MnSb and MnAsSb precipitates are observed by TEM. , While MOVPE-grown (In,Mn)Sb epitaxial films show considerable promise as magnetic semiconductor material, little is known about the nature of Mn substitution in the film and its magnetic properties including T c .…”

Computational investigation of high Curie temperature in a new N‐type ferromagnetic diluted magnetic semiconductors, especially iron‐doped on GaSb

“…[24][25][26][27][28] This diluted magnetic semiconductor device requires a small amount of energy to process, store, and process data simultaneously; it also saves time, space, and money. [29][30][31][32][33][34] Manganese has a partially field 3D shell, but other transition metals do not. Manganese has the ability to create shallow acceptor levels, which are used for special electrical properties.…”

A theoretical model of high Curie temperature for N-type ferromagnetic diluted semiconductors based on iron-doped indium antimonide

“…This type of technology is required if the DMS Curie temperature (T C ) is higher than the room temperature for the application [9]. As is observed, diluted magnetic semiconductor devices not only fill the gap between the magnet and the semiconductor devices but also use it to store, process, and transmit data simultaneously, saving time, space, and money [12][13][14][15][16][17][18].…”