Pressure-induced change of electronic state in samarium nickelate, SmNiO3, around 1.1 GPa: An infrared spectroscopic study

A pressure-induced electronic change of state in samarium nickelate at about 1.1 GPa has been inferred from monitoring changes in the infrared spectrum. These spectral changes are similar to those observed when this material undergoes its (known) ambient pressure temperature-induced insulator-to-metal transition. A similarity has been previously observed between variable temperature and variable pressure electrical measurements on other rare-earth nickelates, and has been suggested to arise because of a similar or identical mechanism for the pressure- and temperature-induced insulator-to-metal transition. Our data is not inconsistent with this suggestion.