Powder neutron diffraction study of the perovskites CaTiO3 and CaZrO3

Redetermination of tricalcium uranate(VI). A Rietveld refinement of neutron powder diffraction data

“…The same structure type is found in CaTiO 3 and CaZrO 3 (Koopmans, van de Velde & Gellings, 1983), but the ordering of the octahedra lowers the spacegroup symmetry from Pbnm to P21/n. Ringwood (1978) stated that in Synroc the U is present in the zirconolith phase.…”

Synthesis and photoluminescence properties of Eu3+-doped AZrO3 (A=Ca, Sr, Ba) perovskite

“…The octahedral tilting can induce the change of Zr-O bong lengths. In AZrO 3 system, the mean Zr-O bond length of SrZrO 3 is the smallest, about 2.091Å [11], while the largest is that of CaZrO 3 , being about 2.097Å [10]. Thus, the degree of covalence of Eu 3+ -O 2− bond is the weakest in SrZrO 3 phosphor because Zr 4+ in this system can attract electrons of O 2− most strongly due to the smallest radius.…”

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

“…To overcome this difficulty, numerous efforts by our research group have been made to understand the mechanism of PL emissions in SrTiO3, SrTiO3:Sm, CaWO4, BaZrO3, and BaZr1-xHfxO3 solid solutions based on the characterization of excited electronic states [31][32][33][34][35][36][37] respectively, as the constituent building blocks of this material [49]. There are several reports on the electronic structure calculations performed to study CZO in the ground state [50][51][52][53][54][55]. Recently, Gupta et al [56] have been performed a spectroscopic and theoretical study to explain the PL emission in the blue region based on the nature of defects, while Moreira et al [57] employed first-principles calculations to clarify the mechanisms involved in the luminescence emissions observed for disordered BaZrO3, proposing a novel explanation for transitions from a PL and to a radioluminescence emission regime based on crystalline defects.…”