Superhard Semiconducting Optically Transparent High Pressure Phase of Boron
2009 (English)In: PHYSICAL REVIEW LETTERS, ISSN 0031-9007, Vol. 102, no 18, 185501- p.Article in journal (Refereed) Published
An orthorhombic (space group Pnnm) boron phase was synthesized at pressures above 9 GPa and high temperature, and it was demonstrated to be stable at least up to 30 GPa. The structure, determined by single-crystal x-ray diffraction, consists of B-12 icosahedra and B-2 dumbbells. The charge density distribution obtained from experimental data and ab initio calculations suggests covalent chemical bonding in this phase. Strong covalent interatomic interactions explain the low compressibility value (bulk modulus is K-300=227 GPa) and high hardness of high-pressure boron (Vickers hardness H-V=58 GPa), after diamond the second hardest elemental material.
Place, publisher, year, edition, pages
2009. Vol. 102, no 18, 185501- p.
IdentifiersURN: urn:nbn:se:liu:diva-18542DOI: 10.1103/PhysRevLett.102.185501OAI: oai:DiVA.org:liu-18542DiVA: diva2:220389