Negative Giant Longitudinal Magnetoresistance in NiMnSb/InSb: An interface effect

TL;DR

This study investigates the negative giant magnetoresistance effect at the interface of NiMnSb and InSb, attributing it to magnetic precipitates formed during film deposition and influenced by thermal processing.

Contribution

It reveals an interface-specific magnetoresistance phenomenon in NiMnSb/InSb systems caused by magnetic precipitates, highlighting the role of thermal treatment.

Findings

Negative GMR observed when magnetic field is parallel to film surface and current.

Magnetoresistance effect linked to magnetic precipitates at the interface.

Thermal processing influences the magnitude of the GMR 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.