12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone
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Red emission of Pr3+ enhancement by addition of Ba2+ and In3+ in CaTiO3:Pr phosphor

Presented by Mr. Luyanda Lunga NOTO on 13 Jul 2011 from 17:00 to 19:00
Type: Poster Presentation
Session: Poster1
Track: Track A - Condensed Matter Physics and Material Science

Content

<p>CaTiO3 exhibits a Perovskite structures that has an ABO3 stochiometry where A and B represent metal cations with a combined charge of 6+ valency and O with 6- valency, and thus bring about charge neutrality to the compound. Upon introducing Pr3+ ions in the site of Ca2+ ions, charge imbalance occurs by introducing a 7+ valency, and this force the material to compensate for this effect by introducing negative Ca & Ti vacancies, and positive O vacancies. These act by hampering the material luminescence. Thus substitution of Ti4+ by co-doping with Ba2+ and In3+ ions result into a 6+ valency and thus an electrically neutral compound. This reinforces the red emission of Pr3+ ions inside CaTiO3. CaTiO3: Pr3+ exhibiting red emission is synthesized via solid state reaction, and its luminescence is enhanced by co-doping with Ba2+ and In3+ that act as charge compensators. This optimal emission of CaTiO3:Pr3+,Ba2+,In2+ is achieved by solid state reaction at 1300 oC for 4h, by direct firing, according to 1:1 molar ratio of TiO2 Anatase and CaCO3 compounds, doping with 0.3 mol%Pr3+ (PrCl3) and charge compensating by adding In3+ (In(NO3)3) and Ba2+ (Ba(NO3)2).The observed 613 nm photoluminescence (PL) peak, when exciting the material with 330 nm ultraviolet light to promote (2p(O) → 3d (Ti)) absorption using the PL spectrometer, is attributed to the 1D2 → 3H4 transition of the Pr3+ ions. The glow curves were measured using Thermo luminescence (TL) spectroscopy. Addition of Ba2+ and In3+ ions into CaTiO3:Pr3+ phosphor enhances the optical performance of the Pr3+ red-emission. Additionally the phase was identified using the X-ray diffraction (XRD) and the surface morphology identified using Scanning Electron Microscopy (SEM).

Level (Hons, MSc, PhD, other)?

MSc

Consider for a student award (Yes / No)?

Yes

Short Paper

Yes

Place

Location:
Room: Asteria


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