Evidence of a low compressibility carbon nitride with defect-zincblende structure

A carbon-nitride compound with defect zincbiende structure (P<(31)over bar>m) has been discovered in samples prepared by a chemical precursor route. Crystallographical (high-resolution electron microscopy and electron nanodiffraction) and electron energy loss measurements has been performed to identify the material as cubic zincblende with C3N4 composition. Nanoindentation indicates a high elastic recovery and hardness. The results agree with detailed ab initio calculations on metastable structures and compressibility. Our synthesis method is projected to be a process that could produce large quantities of material by controlling the chemical strategy. The new compound has potential applications for high hardness, elasticity and thermal conductivity, materials and thin films. (C) 1997 American Institute of Physics.