Cr₂N is commonly found as a minority phase or inclusion in stainless steel, CrN-based hard coatings, etc. However, studies on phase-pure material for characterization of fundamental properties are limited. Here, Cr₂N thin films were deposited by reactive magnetron sputtering onto (0001) sapphire substrates. X-ray diffraction and pole figure texture analysis show Cr₂N (0001) epitaxial growth. Scanning electron microscopy imaging shows a smooth surface, while transmission electron microscopy and X-ray reflectivity show a uniform and dense film with a density of 6.6 g cm⁻³, which is comparable to theoretical bulk values. Annealing the films in air at 400 °C for 96 h shows little signs of oxidation. Nano-indentation shows an elastic–plastic behavior with H = 18.9 GPa and E_r = 265 GPa. The moderate thermal conductivity is 12 W m⁻¹ K⁻¹, and the electrical resistivity is 70 μΩ cm. This combination of properties means that Cr₂N may be of interest in applications such as protective coatings, diffusion barriers, capping layers and contact materials.

Scandium nitride has recently gained interest as a prospective compound for thermoelectric applications due to its high Seebeck coefficient. However, ScN also has a relatively high thermal conductivity, which limits its thermoelectric efficiency and figure of merit (zT). These properties motivate a search for other semiconductor materials that share the electronic structure features of ScN, but which have a lower thermal conductivity. Thus, the focus of our study is to predict the existence and stability of such materials among inherently layered equivalent ternaries that incorporate heavier atoms for enhanced phonon scattering and to calculate their thermoelectric properties. Using density functional theory calculations, the phase stability of TiMgN₂, ZrMgN₂ and HfMgN₂ compounds has been calculated. From the computationally predicted phase diagrams for these materials, we conclude that all three compounds are stable in these stoichiometries. The stable compounds may have one of two competing crystal structures: a monoclinic structure (LiUN₂ prototype) or a trigonal superstructure (NaCrS₂ prototype; R\( \bar{3} \)mH). The band structure for the two competing structures for each ternary is also calculated and predicts semiconducting behavior for all three compounds in the NaCrS₂ crystal structure with an indirect band gap and semiconducting behavior for ZrMgN₂ and HfMgN₂ in the monoclinic crystal structure with a direct band gap. Seebeck coefficient and power factors are also predicted, showing that all three compounds in both the NaCrS₂ and the LiUN₂ structures have large Seebeck coefficients. The predicted stability of these compounds suggests that they can be synthesized by, e.g., physical vapor deposition.

Rock-salt scandium nitride has gained interest due to its thermoelectric properties including a relatively high Seebeck coefficient. This motivates research for other semiconductor materials that exhibit similar electronic structure features as ScN. Using density functional theory calculations, we have studied disordered solid solutions of (Zr_0.5, Mg_0.5)N and (Hf_0.5, Mg_0.5)N using the special quasi-random structure model. The results show that within a mean-field approximation for the configurational entropy, the order–disorder phase transformation between the monoclinic LiUN₂ prototype structure and the rock-salt cubic random alloy of these mentioned solid solutions occur at 740 K and 1005 K for (Zr_0.5, Mg_0.5)N and (Hf_0.5, Mg_0.5)N, respectively. The density-of-states for the two ternary compounds is also calculated and predicts semiconducting behavior with band gaps of 0.75 eV for (Zr_0.5, Mg_0.5)N and 0.92 eV for (Hf_0.5, Mg_0.5)N. The thermoelectric properties of both compounds are also predicted. We find that in the range of a moderate change in the Fermi level, a high Seebeck coefficient value at room temperature can be achieved.

(Ti_0.5, Mg_0.5)N thin films were synthesized by reactive dc magnetron sputtering from elemental targets onto c-cut sapphire substrates. Characterization by θ–2θ X-ray diffraction and pole figure measurements shows a rock-salt cubic structure with (111)-oriented growth and a twin-domain structure. The films exhibit an electrical resistivity of 150 mΩ·cm, as measured by four-point-probe, and a Seebeck coefficient of −25 µV/K. It is shown that high temperature (~800 °C) annealing in a nitrogen atmosphere leads to the formation of a cubic LiTiO₂-type superstructure as seen by high-resolution scanning transmission electron microscopy. The corresponding phase formation is possibly influenced by oxygen contamination present in the as-deposited films resulting in a cubic superstructure. Density functional theory calculations utilizing the generalized gradient approximation (GGA) functionals show that the LiTiO₂-type TiMgN₂ structure has a 0.07 eV direct bandgap.

Based on a Chemical Vapor Deposition (CVD) process, an alumina tube electric furnace was assembled to synthesize different one dimensional aluminum nitride (AIN) nanostructures via aluminum powder and nitrogen gas flow. The products obtained where nanowires, nanorods, a unique chain-linked nanocage structure made from an entanglement of AIN nanowires and an interesting micro-sized spherical architecture. The different growth parameters dictated to the system result the product variety, making structure tuning possible. The incorporation of different substrates (silicon and alumina) not only leads to the formation of different shaped structures, but also results different optical emissions ranging from 450 nm (blue) to 650 nm (red), indicating the high potential of AIN nanostructures in LED fabrication. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selective Area Electron Diffraction (SAED), X-ray Diffraction (XRD), Photoluminescence (PL) and Energy Dispersive X-ray (EDX) analysis results are discussed and a Vapor-Liquid-Solid (VLS)/Vapor-Solid (VS) based growth mechanism is proposed for the mentioned structures.