6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
**Tours now open!** Registration is now closed - All registration payments are due before 23:39 SAST on 26 June.

Influence of the Alkaline Earth Ions (M = Ca2+ and Mg2+) on the Luminescence Properties of doped M-BaB8O13: Gd3+ Phosphor Materials.

7 Jul 2026, 17:20
1h 20m
Great Hall (University of the Western Cape)

Great Hall

University of the Western Cape

Poster Presentation Track C - Photonics Poster Session 1

Speaker

Mr Sabelo Ndlela (University of Johannesburg)

Description

Abstract
Series of Gd3+ doped alkaline earth octaborate phosphors with the general formula MxBa1-xB₈O₁₃: 2% Gd³⁺ (M = Ca²⁺, Mg²⁺; x = 0.10) were synthesized through a solid state method to investigate the influence of alkaline earth ions on the structural, optical, and luminescence properties of the BaB8O13 host material. X-ray diffraction (XRD) confirmed the formation of orthorhombic BaB8O13 showing that the main structure was not influence by the concentration of Ca2+ and Mg2+ but peak shifts and lattice deformation due to the substitution of Ca2+ and Mg2+ ions was observe. Scanning Electron Microscopy (SEM) was perfomed to study the surface morphology, while Energy Dispersive X-ray Spectroscopy (EDS) confirmed elemental composition of the materials. UV-Vis diffuse reflectance spectra and Tauc plot analysis display a narrow bandgap after doping with Gd3+ ions, suggesting change in electronic transitions and an increased defect levels. Photoluminescence (PL) measurements revealed characteristic emissions of Gd3+ under excitation wavelength of 274 nm, with prominent emission intensity at 313 nm wavelength upon doping with Ca²⁺ ions. The observed enhancements are properties to improved energy transfer efficiency around the Gd³⁺ ions, while upon doping with Mg2+ decreased the luminescence intensity and this is due to quenching which led to higher probability of non-radiative energy transfer between Mg2+ ions. These findings prove that controlled substitution with alkaline earth metals can effectively modify the luminescence properties of Gd3+ activated BaB8O13 phosphors, making them promising candidate for phototherapy applications.

Apply for student award at which level: MSc
Consent on use of personal information: Abstract Submission Yes, I ACCEPT

Author

Mr Sabelo Ndlela (University of Johannesburg)

Co-authors

Prof. Buyi Sondezi (University of Johannesburg) Dr Machaba Letswalo (University of Johannesburg)

Presentation materials

There are no materials yet.