Influence of growth temperature on phase and intermixing in Ni2MnIn Heusler films on InAs(001)

Suppression of interfacial intermixing between MBE-grown Heusler alloy Ni2MnIn and (001)InAs or InAs-HEMT structures

“…A strong decrease in the magnetisation after the annealing step is clearly visible. This film degradation may be attributed to intermixing processes discussed previously [12]. In this context, we conclude that the native oxide layer between the InAs substrate and the Heusler film does not act as a diffusion barrier.…”

“…Furthermore, the estimated thickness of the native oxide layer beneath the MgO layer is approximately 5 nm for both samples. Most importantly, the data establish no indication for an intermixed layer, which we have observed for Ni 2 MnIn deposition directly on InAs without MgO layer [12]. From the XRR data of the samples with InAs-HEMT structures, no layer thicknesses could be extracted due to their complex layer structure and surface morphology [3][4][5].…”

“…Our previous investigations [12] revealed an optimal growth temperature for the deposition of Heusler films on (0 0 1)InAs in the desired L2 1 phase of T sub ¼300 1C. However, at this temperature, a strong interfacial intermixing is observed, which reduces the quality of the interface.…”

Structural and magnetic properties of Ni2MnIn Heusler thin films grown on modulation-doped InAs heterostructures with metamorphic buffer

“…The small lattice mismatch eE0.6% between Ni 2 MnIn (a¼0.6024 nm) and InAs (a¼0.6058 nm) is expected to enable good epitaxial lattice matching and a defect-free growth of Heusler thin films. In a previous publication, we reported on the structural and magnetic properties of the Ni 2 MnIn full-Heusler alloy grown on single-crystalline (001) InAs substrates using molecular beam epitaxy [9]. This study demonstrated that a Heusler-layer growth temperature of T S ¼300 1C yields an optimal compromise in view of both the structural as well as magnetic properties.…”

“…A number of half and full Heusler alloys have been investigated as candidates for spin-polarized semi-metallic electrodes [4][5][6][7]. We investigate the full Heusler alloy Ni 2 MnIn [5,[7][8][9]. Band structure calculations of Ni 2 MnIn/InAs (001) without intra-band correlation effects predict a spin-polarization of nearly 100% [10][11][12][13][14] and a high probability for transmission of spin-polarized electrons through the semimetal-semiconductor interface along main crystallographic directions.…”