Electronic structure of fully epitaxial Co${}_{2}$TiSn thin films

Electronic structure of fully epitaxial Co $_{2}$ TiSn thin films

Markus Meinert, Jan Schmalhorst, Hendrik Wulfmeier, Günter Reiss, Elke Arenholz, Tanja Graf, and Claudia Felser

Phys. Rev. B 83, 064412 – Published 15 February 2011

Abstract

We report on the properties of thin films of the full Heusler compound Co $_{2}$ TiSn prepared by dc magnetron co-sputtering. Fully epitaxial, stoichiometric films were obtained by deposition on MgO (001) substrates at substrate temperatures above $600^{°}$ C. The films are well ordered in the $L 2_{1}$ structure, and the Curie temperature slightly exceeds the bulk value. They show a significant, isotropic magnetoresistance and the resistivity becomes strongly anomalous in the paramagnetic state. The films are weakly ferrimagnetic, with nearly 1 $μ_{B}$ on the Co atoms, and a small antiparallel Ti moment, in agreement with theoretical expectations. From comparison of x-ray absorption spectra on the Co $L_{3, 2}$ edges, including circular and linear magnetic dichroism, with ab initio calculations of the x-ray absorption and circular dichroism spectra we infer that the electronic structure of Co $_{2}$ TiSn has essentially nonlocalized character. Spectral features that have not been explained in detail before are explained here in terms of the final-state band structure.