Experimental verification of the ab initio phase transition sequence in SrZrO3 and comparisons with SrHfO3 and SrSnO 3

Abstract

Dielectrics: into a new phase An unexpected atomic arrangement in a material useful for electronics is identified by researchers in India, the UK, and the USA. Ashok Kumar from the CSIR-National Physical Laboratory and co-workers observe a phase change in strontium zirconate at 650 K. Strontium zirconate is an electrical insulator that has great potential in the semiconductor-technology because of its large dielectric constant. As this so-called perovskite is heated, its atomic structure changes at specific temperatures. But the sequence of these phase changes is still a matter of debate. Kumar and colleagues study the structure of strontium zirconate by measuring the optical emission associated with atomic vibrations—a method known as Raman spectroscopy and dielectric spectroscopy. They identify three anomalous features in these results that infer the presence of a new phase transition.