Atomically Resolved Defects on Thin Molybdenum Carbide (α-Mo2C) Crystals

Abstract

Thintransition metal carbides (TMCs) garnered significant attentionin recent years due to their attractive combination of mechanicaland electrical properties with chemical and thermal stability. Onthe other hand, a complete picture of how defects affect the physicalproperties and application potential of this emerging class of materialsis lacking. Here, we present an atomic-resolution study of defectson thin crystals of molybdenum carbide (& alpha;-Mo2C) grownvia chemical vapor deposition (CVD) by way of conductive atomic forcemicroscopy (C-AFM) measurements under ambient conditions. Defectsare characterized based on the type (enhancement/attenuation) andspatial extent (compact/extended) of the effect they have on the conductivitylandscape of the crystal surfaces. Ab initio calculationsperformed by way of density functional theory (DFT) are employed togather clues about the identity of the defects.