Speaker
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Prof M. S Dhlamin, dhlamms@unisa.ac.za, Department of Physics, University of South Africa, P. O. Box 392, 0003
Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)
yes
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
Due to its optical, magnetic, electrical and catalytic properties, iron oxide has attracted attention of researchers from different areas of science. α-Fe2O3 is an environmentally friendly n-type semiconductor with the band gap of ~2.1 eV. It is the most stable iron oxide under ambient conditions. It is widely used in gas sensing, high density magnetic recording media, clinical therapy, Magnetic resonance imaging and diagnosis [1-3]. Rare earth atoms recently have been introduced into the iron oxide matrix which leads to a material that shows multiple interesting effects. Holmium atoms were incorporated into an iron oxide nanoparticle and the concentration of the dopant atom was changed in order to determine its influence on the host crystal.
Un-doped and doped α-Fe2O3 particles were successfully synthesized by sol-gel method using PVA as polymerizing agent. The main advantage of PVA is to provide long stability for nanoparticles and by preventing the particles agglomeration. The synthesized powder was separated and annealed at different temperatures. The shape, size, structural and lumenescence studies of the synthesized powder were characterized by XRD, TEM, FT-IR, UV-Vis and PL spectral techniques. A high crystallinity was observed with increasing annealing temperature by XRD. An increase in absorbance and a red shift was observed with increasing annealing temperature. The estimated band gaps of the powders were found to be 5.5 eV and 2.3 eV for powders at 300°C and 600°C respectively. Un-doped and doped Fe2O3 samples were subjected to radiation from the laser beam source to investigate anti-stokes luminescence.
References
1. M. N Batin and V. Popesca, optoelectronics and advanced materials-rapid communications, Vol. 6, 2012, 727-729
