Unexpected origin of magnetism in monoclinic Nb12O29 from first-principles calculations

Nb12O29 is a 4d transition metal oxide that occurs in two forms with different symmetries, monoclinic (m) and orthorhombic (o). The monoclinic form has unusual magnetic properties; below a temperature of 12 K, it exhibits both metallic conductivity and antiferromagnetic ordering. Here, first-principles density-functional theory calculations are...

Novel ultrafine Fe(C) precipitates strengthen transformation-induced-plasticity steel

A transmission electron microscopy study was conducted on nanoprecipitates formed in Ti microalloyed transformation-inducedplasticity-assisted steels, revealing the presence of Ti(N), Ti2CS and a novel type of ultra-fine Fe(C) precipitate. The matrix/precipitate orientation relationships, sizes and shapes were investigated in detail. The...

Characterization of NbC and (Nb, Ti)N nanoprecipitates in TRIP assisted multiphase steels

Multiphase steels utilising composite strengthening may be further strengthened via grain refinement or precipitation by the addition of microalloying elements. In this study a Nb microalloyed steel comprising martensite, bainite and retained austenite has been studied. By means of transmission electron microscopy (TEM), we have investigated the...