Chromium nitride is a transition metal nitride material that crystallizes in cubic crystal structure at room temperature. In thin film form, it shows first-order structural and magnetic phase transitions at Néel temperature (280±2 K)<sup>1</sup> from paramagnetic state with cubic crystal structure to antiferromagnetic state with orthorhombic/tetragonal crystal structure at low temperatures<sup>1,2</sup>. However, there are many controversial reports about its electronic phase transition that call for a fresh investigation with novel methods. In this project, a complete set of experiments has been designed to study the electronic properties of CrN thin films grown by reactive radio frequency sputtering. Thin films with different Cr to N atomic ratios and layer thicknesses have been prepared to study their effects on the electronic phase transition and band gap of CrN. All films show electronic phase transitions from semiconductor state at room temperature to metallic or semiconducting state at low temperatures. The low temperature metallic and semiconducting states depend on the growth conditions and stochiometric ratios of the films. The band gap at room temperature is found to be highly sensitive to the stochiometric ratio of the film. X-ray photoelectron spectroscopy and Raman spectroscopy have been used for studying the stoichiometry and four probe variable temperature resistivity setup has been used for studying the electronic transition. The optical band gap has been measured by recording transmittance spectra of the films.

Electronic phase transition in chromium nitride thin films at low temperatures

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.