4 years ago

Unexpected Trend Deviation in Isoelectronic Transition Metal Borides A3T5B2 (A = group 4, T = group 9): Ti3Co5B2- vs. Perovskite-Type Studied by Experiments and DFT Calculations

Unexpected Trend Deviation in Isoelectronic Transition Metal Borides A3T5B2 (A = group 4, T = group 9): Ti3Co5B2- vs. Perovskite-Type Studied by Experiments and DFT Calculations
Boniface P. T. Fokwa, Pritam Shankhari, Jan P. Scheifers, Kunio Yubuta, Martin Hermus
We present the first bulk synthesis of Ti3Co5B2, which was realized by arc-melting a Co-rich elemental mixture. Our X-ray diffraction studies revealed a Ti/Co mixed occupancy on one of two possible Ti sites suggesting a phase width with x = 0–0.52 in Ti3–xCo5+xB2. Moreover, we studied experimentally and theoretically the isoelectronic substitution of Ti and Co by their respective higher homologues (Zr/Rh and Hf/Ir). Surprisingly, Ti3Co5B2-type phase was obtained only for the Hf/Ir combination (single crystal analysis of Hf3Ir5B2), whereas for Zr/Rh a perovskite-like phase (ZrRh3Bx) was discovered instead. We found that small but crucial differences (atomic radius ratio and electronegativity difference) between elements of the same group in the periodic Table are responsible for the unexpected trend deviation. This finding is supported by DFT calculations of the free energy of formation.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/zaac.201700271

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.