title: Synthesis of (Ca,Nd)TiO3 powders by complex polymerization, Rietveld refinement and optical properties.
abstract: Neodymium calcium titanate, (Ca(0.99)Nd(0.01))TiO(3) powders were synthesized by the complex polymerization method and heat treated at different temperatures for 2 h under air atmosphere. The structural evolution of these powders as a function of heat treatment temperature was analyzed by X-ray diffraction (XRD) and micro-Raman (MR) spectroscopy. The optical properties were investigated by Ultraviolet-visible (UV-vis) absorption spectroscopy and Photoluminescence (PL) measurements. XRD patterns, Rietveld refinement and MR spectra indicated that the powders heated treated at 750 degrees C for 2 h present an orthorhombic structure without secondary phases. UV-vis measurements suggested the presence of intermediary energy in disordered (Ca(0.99)Nd(0.01))TiO(3) powders. Broad and narrow bands were observed in the PL spectra of these powders when excited with 350 nm wavelength. The broad bands were associated to the structural defects and/or p-d electronic transitions while, the narrow bands were ascribed to f-f transitions arising from Nd(3+) ions.
authors.affiliation: CCN-Química, Universidade Federal do Piauí, 64049-550, Teresina, PI, Brazil.
authors.forename: V S
authors.initials: VS
authors.lastname: Marques
authors.forename: L S
authors.initials: LS
authors.lastname: Cavalcante
authors.forename: J C
authors.initials: JC
authors.lastname: Sczancoski
authors.forename: E C
authors.initials: EC
authors.lastname: Paris
authors.forename: J M C
authors.initials: JM
authors.lastname: Teixeira
authors.forename: J A
authors.initials: JA
authors.lastname: Varela
authors.forename: F S
authors.initials: FS
authors.lastname: De Vicente
authors.forename: M R
authors.initials: MR
authors.lastname: Joya
authors.forename: P S
authors.initials: PS
authors.lastname: Pizani
authors.forename: M Siu
authors.initials: MS
authors.lastname: Li
authors.forename: M R M C
authors.initials: MR
authors.lastname: Santos
authors.forename: E
authors.initials: E
authors.lastname: Longo
mesh_terms: D001272:Atmosphere; D002104:Cadmium / Q000737:chemistry*; D004583:Electrons; D008163:Luminescent Measurements; D008956:Models, Chemical; D009354:Neodymium / Q000737:chemistry*; D055620:Optical Phenomena; D011108:Polymers / Q000737:chemistry*; D011208:Powders / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D011108:Polymers; D011208:Powders; D002104:Cadmium; C009495:titanium dioxide; D009354:Neodymium; D014025:Titanium