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arXiv · 1509.00326

Pressure induced novel compounds in the Hf-O system from first-principles calculations

Jin Zhang·Artem R. Oganov·Xinfeng Li·Kan-Hao Xue·Zhenhai Wang·Huafeng Dong
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Abstract

Using first-principles evolutionary simulations, we have systematically investigated phase stability in the Hf-O system at pressure up to 120 GPa. New compounds Hf5O2, Hf3O2, HfO and HfO3 are discovered to be thermodynamically stable at certain pressure ranges and a new stable high-pressure phase is found for Hf2O with space group Pnnm and anti-CaCl2-type structure. Both P62m-HfO and P4m2-Hf2O3 show semimetallic character. Pnnm-HfO3 shows interesting structure, simultaneously containing oxide O2- and peroxide [O-O]2- anions. Remarkably, it is P62m-HfO rather than OII-HfO2 that exhibits the highest mechanical characteristics among Hf-O compounds. Pnnm-Hf2O, Imm2-Hf5O2, P31m-Hf2O and P4m2-Hf2O3 phases also show superior mechanical properties, these phases can be quenched to ambient pressure and their properties can be exploited.

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Jin Zhang, Artem R. Oganov, Xinfeng Li, Kan-Hao Xue, Zhenhai Wang, Huafeng Dong. 2015-09-01. Pressure induced novel compounds in the Hf-O system from first-principles calculations. https://doi.org/10.1103/physrevb.92.184104

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