TiGe thin film

Weyl Semimetals (WSM) are interesting class of topological materials where Weyl fermions have been realized [1] with distinct chirality. Recent theoretical predictions have shown the time-reversal symmetry breaking in the full Heusler alloy Co2TiGe [2,3] which can create a new heterostructure spintronics devices that combine the diverse physical properties of Heusler compounds. We have presented the fabrication, magnetic and transport properties of Co2TiGe thin films prepared on Si (100) substrates by electron-beam evaporation in ultra-high vacuum. Thin films exhibit L21 crystal structure and saturation magnetic moment of 1.9 μ_B/f.u. at 10 K with a Curie temperature of 380 K. Magnetotransport properties on the thin films reveal semimetallic resistivity, small anomalous Hall resistivity and weak-localization. The anomalous Hall resistivity is proportional to square of longitudinal resistivity, which is due to the topological Berry curvature.
1) S. Y. Xu et. al, Science 349, 613 (2015).
2) G. Chang et. al, Sci. Rep. 6, 38839 (2016).
3) Z. Wang et. al, Phys. Rev. Lett. 117, 236401 (2016).36401 (2016).