Impact of Nanostructuration on the Chemical Composition of Nickel Oxide Nanoparticles.

Reduction of the size of a particle down to a few tens of nanometers or below may drastically affect its physical properties. That is well-known for quantum dots. Conversely, many works consider the chemical composition of nanoparticles as invariant upon reduction of their dimension.

Experimental and Theoretical Evidences of p-Type Conductivity in Nickel Carbodiimide Nanoparticles with a Delafossite Structure Type.

Nickel carbodiimide (NiCN) was synthesized using a two-step precipitation-decomposition route leading to a brown powder with gypsum-flower-like morphology and a large specific surface area (75 m/g). This layered material crystallizes in the 2H structure type of delafossite (space group P6/mmc), which is built upon infinite /[NiN] layers connected by linear carbodiimide ([N═C═N]) bridges. An X-ray diffraction Rietveld refinement and thermal analyses pointed out some nickel deficiencies in the material, and band structure calculations carried out on the defect compound predicted p-type conductivity in relation to a slight amount of N.