Crystal structure and phase stability of tungsten borides

POSTER

Abstract

We address the longstanding and controversial issue of ground-state structures of technically important tungsten borides using a first-principles structural search method via a particle-swarm optimization (PSO) algorithm. We have explored a large set of stable chemical compositions (convex hull) and clarified the ground-state structures for a wide range of boron concentrations, including W$_2$B, W$_3$B$_2$, WB, W$_2$B$_3$, WB$_2$, W$_2$B$_5$, WB$_3$, and WB$_4$. We further assessed relative stability of various tungsten borides and compared the calculated results with previously reported experimental data. The phase diagram predicted by the presented calculations may serve as a useful guide for synthesis of a variety of tungsten borides.

*This work was supported by DOE Grant No. DE-FC52-06NA26274.

Authors

  • Quan Li

    • Department of Physics and High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, USA

  • Dan Zhou

    • Department of Physics and High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, USA

  • Yanming Ma

    • State key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
    • State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China

  • Changfeng Chen

    • Department of Physics and High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, USA