Among transition metal nitrides, molybdenum nitrides have been much less studied even though their mechanical properties as well as their electrical and catalytic properties make them very attractive for many applications. The δ-MoN phase of hexagonal structure is a potential candidate for an ultra-incompressible and hard material and can be compared with c-BN and diamond. The predicted superconducting temperature of the metastable MoN phase of NaCl-B1-type cubic structure is the highest of all refractory carbides and nitrides. The composition of molybdenum nitride films as well as the structures and properties depend on the parameters of the process used to deposit the films. They are also strongly correlated to the electronic structure and chemical bonding. An unusual mixture of metallic, covalent and ionic bonding is found in the stoichiometric compounds.
The crystallization of the Bi 0.5 Nb 0.5 Te 3 O 8 (7.14 Bi 2 O 3 − 7.14Nb 2 O 5 −85.72TeO 2 ) glass composition shows numerous original spherulite-like shape or "droplets" crystalline domains through the bulk. Both SEM-EDS and microprobe measurements demonstrate that both these droplets and the glassy matrix present the same composition. The combination of information obtained from various complementary techniques, electron probe microanalysis, Raman, and SEM-EDS, then leads to the identification of the spherulites as a new Bi 0.5 Nb 0.5 Te 3 O 8 "anti-glass" phase. However, the crystallization mechanism is complex since microcracks are observed at the surface of the spherulites in some glass-ceramic materials, suggesting a confined crystal growth. Therefore, the crystallization process appears much different from a homogeneous congruent crystallization. The photoluminescence (PL) properties of the (1 wt %) Er 2 O 3 -doped Bi 0.5 Nb 0.5 Te 3 O 8 glass-ceramics were investigated during isothermal crystallization of the parent glass at 380 °C. The evolution of the PL signal ( 4 I 13/2 → 4 I 15/2 transition) enables indirect detection of the first steps of crystallization. Moreover, the PL data indicate random nucleation with respect to the location of Er 3+ ions, whereas the integrated PL intensity and lifetime values show very comparable evolution trends as a function of the crystallization rate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.