Complex crystal structure and photoluminescence of Bi-doped and Bi/Eu co-doped CaMgGaO.

Recently, broad-band white-light-emitting using Eu2+, Ce3+, or Bi3+ in multi-sites of a single-phase phosphor have drawn extensive attention due to their potential to realize high-quality indoor lighting. This work reports a novel oxide, Ca7Mg2Ga6O18 (CMG), possessing a complex crystal structure in the space group F432. Rietveld refinements of high-resolution synchrotron X-ray diffraction data were performed to determine the accurate atomic positions and occupancy factors, giving a reasonable composition of Ca7Mg1.

Site-selective doping effect, phase separation, and structure evolution in 1:1:1 triple-cation B-site ordered perovskites Ca Sr GaNbO.

Oxygen-deficient perovskites are a family of important materials that may exhibit oxide ionic conductivities. We attempted to introduce oxygen-vacancy disordering in perovskite CaGaNbO (Ca-type) by substituting Ca with larger Sr. Sr-to-Ca substitution did not lead to oxygen-vacancy ordering-disordering transition but an interesting Ca-to-Sr type structure transition.

Optimizing the performance of photocatalytic H generation for ZnNbO synthesized by a two-step hydrothermal method.

Semiconductor-based photocatalytic H generation is a promising technique and the development of efficient photocatalysts has attracted great attention. Columbite-ZnNbO is a wide-bandgap semiconductor capable of photocatalytic water splitting. Here we employed a two-step hydrothermal method to first dissolve NbO with a highly basic aqueous solution and further react it with Zn to form nanosized ZnNbO.