Structural, magnetic, and transport properties of Fe-doped CoTiSb epitaxial thin films

Abstract

Epitaxial intrinsic and Fe-doped CoTiSb thin films with C1b structure were grown on MgO(100) substrates by magnetron sputtering. The semiconducting-like behavior in both intrinsic and Fe-doped thin films was demonstrated by temperature dependence of longitudinal resistivity. The Fe-doped CoTiSb films with a wide range of doping concentrations can maintain semiconducting-like and magnetic properties simultaneously, while the semiconducting behavior is weakening with the increasing Fe concentration. For 21 at. % Fe-doped film, low lattice magnetic moment (around 0.65 μB) and high resistivity (larger than 800 μΩ cm) are beneficial to its application as a magnetic electrode in spintronic devices. Anomalous Hall effect of 21 at. % Fe-doped film was also investigated and its behaviors can be treated well by recent-reported anomalous Hall scaling including the contribution of spin-phonon skew scattering.

Growth, electrical, structural, and magnetic properties of half-Heusler CoTi1−xFexSb

“…3(b). For the CoTiSb spectrum, good agreement is observed with the DOS and resembles previously reported spectra at similar excitation energies 16,18,32,35 . For the x=0.2 and x=0.5 films, the spectra show similar structure to that of CoTiSb with only a few small binding energy shifts, consistent with our calculated DOS.…”

“…A high residual resistivity and thermally activated transport has been observed within other predicted half-metallic f-H compounds 41,42 and may originate from disorder within a half-metallic system. The observed temperature dependence is consistent with previous reports of sputtered films, where thermally activated behavior was observed for films up to 37 atomic % of Fe 18 .…”

“…However, for many device applications thin films are a necessary requirement. Previous work by Sun et al 18 reported the growth and properties of Fe alloyed CoTiSb epitaxial thin films prepared by the magnetron sputtering method. For the intrinsic CoTiSb thin films, carrier concentrations of ~10 21 cm -3 and mobilities of ~2 cm 2 /V-s at room temperature were reported, which was attributed to Ti-deficiency.…”