Negative giant longitudinal magnetoresistance inNiMnSb∕InSb: Interface effect

Abstract

We report on the electrical and magneto-transport properties of the contact formed between polycrystalline NiMnSb thin films grown using pulsed laser deposition (PLD) and n-type degenerate InSb (100) substrates. A negative giant magnetoresistance (GMR) effect is observed when the external magnetic field is parallel to the surface of the film and to the current direction. We attribute the observed phenomenon to magnetic precipitates formed during the magnetic film deposition and confined to a narrow layer at the interface. The effect of these precipitates on the magnetoresistance depends on the thermal processing of the system.

Negative magnetoresistance in indium antimonide whiskers doped with tin

“…Figure 1 shows the longitudinal magnetoresistance (B parallel to the wire axis) for InSb whiskers with impurity concentration 3.26⋅10 17 cm -3 , which corresponds to MIT at temperature 4.2 K. The maximum ratio ΔR/R increases approaching to MIT and reaches 50% at 4.2 K. As the temperature rise, the maximum value decreases (up to 15% at temperature 42 K). The observed NMR effect is like that of the reference [15] for NiMn/InSb structure. According to data [15] the NMR cannot be explained by disorder effect [16], and by the scattering of the conduction electrons by localized spins through an s-d exchange interaction [17].…”

“…The observed NMR effect is like that of the reference [15] for NiMn/InSb structure. According to data [15] the NMR cannot be explained by disorder effect [16], and by the scattering of the conduction electrons by localized spins through an s-d exchange interaction [17]. An explanation of the NMR is the interface containing microscopic magnetic entities (NiMn or Ni precipitates).…”

“…An explanation of the NMR is the interface containing microscopic magnetic entities (NiMn or Ni precipitates). Upon increasing the magnetic field, these magnetic entities gradually align their magnetic moments with the external magnetic field leading to a decrease in the spin-dependent resistance of the system [15].…”

Quantization in magnetoresistance of strained InSb whiskers

“…Compressively-strained bulk InSb demonstrated the highest hole mobility close to 1000 cm 2 /(V•s) at room temperature [7]. Negative magnetoresistance (NMR) corresponding to different mechanisms of charge carrier scattering was found in such material as InSb at weak magnetic fields and lowtemperature range [10][11][12][13][14][15][16][17][18][19]. NMR phenomena with strong spin-orbital coupling gaps were revealed in topological semimetals [10].…”

“…The presence of magnetic ordering in InSb thin films due to introducing of the magnetic impurities such as Mn actually leads to the observation of NMR in the field dependences of the magnetoresistance [14][15][16][17][18][19]. NMR phenomena along with the Shubnikov-de Haas oscillation effect was also found in InSb whiskers with a doping concentration of Sn in the vicinity to metal-insulator transition (MIT) from mеtal and insulator side of the transition at magnetic field up to 10 T in the temperature range 4.2-77 K [20,21].…”