biostudies-otherUnknown6Xing WScientific reports21794https://www.ebi.ac.uk/biostudies/studies/S-EPMC4772090Transition metal compounds usually have various stoichiometries and crystal structures due to the coexistence of metallic, covalent, and ionic bonds in them. This flexibility provides a lot of candidates for materials design. Taking the V-C binary system as an example, here we report the first-principles prediction of a new type of vanadium carbide, V5C3, which has an unprecedented stoichiometry in the V-C system, and is energetically and mechanically stable. The material is abnormally much harder than neighboring compounds in the V-C phase diagram, and can be further hardened by tuning the Fermi energy.biostudies-otherEurope PMCMeng FXing WYu RfalseA new type of vanadium carbide V5C3 and its hardening by tuning Fermi energy.Transition metal compounds usually have various stoichiometries and crystal structures due to the coexistence of metallic, covalent, and ionic bonds in them. This flexibility provides a lot of candidates for materials design. Taking the V-C binary system as an example, here we report the first-principles prediction of a new type of vanadium carbide, V5C3, which has an unprecedented stoichiometry in the V-C system, and is energetically and mechanically stable. The material is abnormally much harder than neighboring compounds in the V-C phase diagram, and can be further hardened by tuning the Fermi energy.2016-01-01T00:00:00Z20162019-08-03T07:29:56Z2019-08-03T07:29:56ZS-EPMC477209010.1038/srep21794