Use of low temperature solvothermal reactions in the synthesis of nanocrystalline tantalum nitrides including nanorods

Solvothermal reactions of TaCl5 with LiNH2 or Mg3N2 lead to amorphous products at temperatures up to 500 °C. Post-reaction annealing under nitrogen yields crystalline products with Ta3N5 (LiNH2) and TaN (Mg3N2) structures. When these reactions are carried out with LiNH2 in refluxing mesitylene, rods of Ta3N5-structured material are obtained. Using commercial LiNH2 these have dimensions of 5 × 200 nm but are contaminated with LiTaO3. With high purity LiNH2 a black oxide-free but carbon-containing material presents as rods of 20–50 nm length. Higher temperature reactions in an autoclave lead to isotropic nanocrystals of ca. 10 nm diameter of a nitrogen-deficient or carbide-substituted Ta3N5-type material. Carbon incorporation is attributed to solvent decomposition at the temperatures required for the reactions. The TaN derived from reactions with Mg3N2 consists of nanoparticles of 6–8 nm in diameter

Solution phase preparative routes to nitride morphologies of interest in catalysis

This review assesses the track record and prospects of non-oxide sol–gel and solvothermal routes to nitride materials for use in catalysis. There is a strongly developing body of synthesis methods that yield highly porous materials, some with engineered pore structures, nanocrystalline materials with high surface areas and anisotropic nanocrystals that have their surface area tuned to a particular crystal face. Most of the existing catalytic work on such solution-derived nitrides has focussed on utilising base properties due to surface bound amide and imide groups in silicon (imido)nitride compositions, but there are opportunities to extend these methods to other interesting nitride compositions

Synthesis and applications of nanocrystalline nitride materials

Most current applications of nitride materials are based on films deposited from the vapour phase. However, a series of other potential uses of nitrides have been envisaged based on properties such as higher conductivity than oxides, hardness, inertness and catalytic or electrochemical activity. Many current applications use nanocrystalline nitrides and increasingly the size and shape dependent properties are of interest. This feature article reviews synthesis methods to make nanocrystalline and nanoparticulate nitride materials, plus it discusses the current applications and several potential ones

Physics of the field evaporation of poor conducting materials in the Laser assisted Atom Probe Tomography

ROUEN-BU Sciences Madrillet (765752101) / SudocSudocFranceF

New Atom Probe Tomography Reconstruction Algorithm for Multilayered Samples: Beyond the Hemispherical Constraint

International audienc

New Atom Probe Tomography Reconstruction Algorithm for Multilayered Samples: Beyond the Hemispherical Constraint

International audienc