Thermal expansion in BaRuO3 perovskites - an unusual case of bond strengthening at high temperatures

Paula Kayser; Sean Injac; Brendan J Kennedy; Andre L Menezes de Oliveira; Yuichi Shirako; Masashi Hasegawa

doi:10.1039/c6dt04473e

Thermal expansion in BaRuO₃ perovskites - an unusual case of bond strengthening at high temperatures

Dalton Trans. 2017 Feb 28;46(9):2974-2980. doi: 10.1039/c6dt04473e.

Authors

Paula Kayser¹, Sean Injac¹, Brendan J Kennedy¹, Andre L Menezes de Oliveira¹, Yuichi Shirako², Masashi Hasegawa²

Affiliations

¹ School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia. [email protected].
² Department of Crystalline Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.

PMID: 28198491
DOI: 10.1039/c6dt04473e

Abstract

The temperature dependences of the structures of three polytypes of BaRuO₃ have been investigated between room temperature and 1000 °C using high resolution synchrotron X-ray diffraction. The structural studies reveal a systematic decrease of the Ru-Ru distance as the pressure required to prepare the polytype increases. The O-O distance across the shared face increases as the Ru-Ru separation decreases. The 9R and 4H polytypes undergo unexceptional changes with increasing temperature. In 6H-BaRuO₃ there is an apparent increase in the Ru-Ru interaction at around 650 °C and a concurrent reduction in the O-O distance, indicating an anomalous strengthening of the Ru-Ru interactions upon heating.