Electronic phase transition in strongly correlated materials is extremely sensitive to the dimensionality and crystallographic orientations. Transition metal nitrides (TMNs) are seldom investigated due to the difficulty in fabricating the high-quality and stoichiometric single crystals. In this letter, we report the epitaxial growth and electronic properties of CrN films on different-oriented NdGaO3 (NGO) substrates. Astonishingly, the CrN films grown on (110)-oriented NGO substrates maintain a metallic phase, whereas the CrN films grown on (010)-oriented NGO substrates are semiconducting. We attribute the unconventional electronic transition in the CrN films to the strongly correlation with epitaxial strain. The effective modulation of bandgap by the anisotropic strain triggers the metal-to-insulator transition consequently. This work provides a convenient approach to modify the electronic ground states of functional materials using anisotropic strain and further stimulates the investigations of TMNs.
@article{arxiv.2111.10566,
title = {Anisotropic electronic phase transition in CrN epitaxial thin films},
author = {Qiao Jin and Jiali Zhao and Manuel Roldan and Shan Lin and Shengru Chen and Haitao Hong and Yiyan Fan and Dongke Rong and Haizhong Guo and Chen Ge and Can Wang and Jia-Ou Wang and Shanmin Wang and Kui-juan Jin and Er-Jia Guo},
journal= {arXiv preprint arXiv:2111.10566},
year = {2022}
}