Effect of Strain on the Physical Properties of Lanthanum Nickelate

Lanthanum nickelate (LaNiO₃) is a promising material for stable fuel-cell electrode, optoelectronic and magneto-electronic devices. Density functional theory (DFT) based calculations were carried out to investigate the effect of strain on the physical properties of the correlated metal LaNiO₃. Electronic structure, optical conductivity and temperature variation of resistivity have been studied in detail using GGA+U approach. It has been observed that LaNiO₃ under strain is more metallic compared to the unstrained system. However LaNiO₃ under compressive strain is found to be more metallic than that under tensile strain. Electron localization function calculation revealed that LaNiO₃ under tensile strain has more covalent bonding than that under compressive strain, which results in an increase in resistivity for the system under tensile strain. The theoretical understanding of the alternation of physical properties of the system, caused by misfit strain may help in the application of the system in different device purposes using strain engineering.