title: Anomalous resistivity upturn in epitaxial L21-Co2MnAl films.
abstract: Despite of the great scientific and technology interest, highly ordered full-Heusler L21-Co2MnAl films have remained a big challenge in terms of the availability and the electrical transport. Here we report the controllable growth and the intriguing transport behavior of epitaxial L21-Co2MnAl films, which exhibit a low-temperature (T) resistivity upturn with a pronounced T1/2dependence, a robust independence of magnetic fields, and a close relevance to structural disorder. The resistivity upturn turns out to be qualitatively contradictory to weak localization, particle-particle channel electron-electron interaction (EEI), and orbital two-channel Kondo effect, leaving a three-dimensional particle-hole channel EEI the most likely physical source. Our result highlights a considerable tunability of the structural and electronic disorder of magnetic films by varying growth temperature, affording unprecedented insights into the origin of the resistivity upturn.
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083, China.|Cornell University, Ithaca, NY 14850, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083, China.
authors.forename: J H
authors.initials: JH
authors.lastname: Zhao