Anisotropic electronic phase transition in CrN epitaxial thin films
Qiao Jin, Jiali Zhao, Manuel A. Roldán, Weiheng Qi, Shan Lin, Shengru Chen, Haitao Hong, Yiyan Fan, Dongke Rong, Haizhong Guo, Chen Ge, Can Wang, Jiaou Wang, Shanmin Wang, Kuijuan Jin, Er‐Jia Guo
Abstract
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 high-quality and stoichiometric single crystals. In this Letter, we report the epitaxial growth and electronic properties of CrN films grown on different-oriented NdGaO3 (NGO) substrates. Astonishingly, 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 phase transitions in CrN films to the strain effects. 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.