Modification of the structural order of transition metal-carbon systems by the addition of a Group VIII element

A Transition-metal carbides M-C from different groups of the periodic table (IVA-VIA), doped with iron, were produced by sputtering, and their chemical composition and crystal structure were evaluated. The M-C binary thin films have different ranges of structural order depending on their heat of formation and tendency to crystallize to a structure of the NaCl type. Iron provokes a significant decrease of the range of structural order of these carbides. The iron content required for the appearing of structures with intermediate-range order is a function of the constituent transition metal of the carbide, and is higher for stronger carbide formers. (C) 2002 Elsevier Science B.V. All rights reserved.