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dc.contributor.authorZhang, R. F.
dc.contributor.authorLegut, Dominik
dc.contributor.authorLin, Z. J.
dc.contributor.authorZhao, Y. S.
dc.contributor.authorMao, H. K.
dc.contributor.authorVepřek, Stanislav
dc.date.accessioned2012-08-01T07:06:33Z
dc.date.available2012-08-01T07:06:33Z
dc.date.issued2012
dc.identifier.citationPhysical review letters. 2012, vol. 108, issue 26, art. no. 255502.cs
dc.identifier.issn0031-9007
dc.identifier.issn1079-7114
dc.identifier.issn1092-0145
dc.identifier.urihttp://hdl.handle.net/10084/94944
dc.description.abstractUsing density functional theory, we show that the long-believed transition-metal tetraborides (TB4) of tungsten and molybdenum are in fact triborides (TB3). This finding is supported by thermodynamic, mechanical, and phonon instabilities of TB4, and it challenges the previously proposed origin of superhardness of these compounds and the predictability of the generally used hardness model. Theoretical calculations for the newly identified stable TB3 structure correctly reproduce their structural and mechanical properties, as well as the experimental x-ray diffraction pattern. However, the relatively low shear moduli and strengths suggest that TB3 cannot be intrinsically stronger than c-BN. The origin of the lattice instability of TB3 under large shear strain that occurs at the atomic level during plastic deformation can be attributed to valence charge depletion between boron and metal atoms, which enables easy sliding of boron layers between the metal ones.cs
dc.format.extent2761598 bytescs
dc.format.mimetypeapplication/pdfcs
dc.language.isoencs
dc.publisherAmerican Physical Societycs
dc.relation.ispartofseriesPhysical review letterscs
dc.relation.urihttp://dx.doi.org/10.1103/PhysRevLett.108.255502cs
dc.titleStability and strength of transition-metal tetraborides and triboridescs
dc.typearticlecs
dc.identifier.locationNení ve fondu ÚKcs
dc.identifier.doi10.1103/PhysRevLett.108.255502
dc.rights.accessopenAccess
dc.type.versionsubmittedVersion
dc.type.statusPeer-reviewedcs
dc.description.sourceWeb of Sciencecs
dc.description.volume108cs
dc.description.issue26cs
dc.description.firstpageart. no. 255502cs
dc.identifier.wos000305568700016


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