Farida Selim, Bowling Green State University, Positron Annihilation Spectroscopy and Measurements of Origin of Novel Electronic Phenomena in Semiconductors and Oxides

Date: Mon. November 20th, 2017, 12:45 pm-1:45 pm
Location: Rockefeller 221 (Les Foldy Room)
Website: http://physics.bgsu.edu/selimlab/

Positron Annihilation Spectroscopy and Measurements of Origin of Novel Electronic Phenomena in Semiconductors and Oxides    

Farida A. Selim, Department of Physics and Astronomy, Bowling Green State University  

Center for Photochemical Sciences, Bowling Green State University

 Positron Annihilation Spectroscopy (PAS) has been established as an effective tool to probe electron states and measure atomic scale defects in solids. However, when combined with other techniques, PAS becomes also a powerful tool for revealing and explaining many interesting electronic phenomena. In our laboratory, we combined PAS with structural and transport measurements as well as with infrared, optical and luminescence spectroscopies to study the electronic properties of wide band gap oxides. 

In this talk, I will present the basics of positron annihilation and describe its various techniques. Then I will present our recent measurements of novel electronic phenomena in SrTiO3 and the role of PAS in revealing the source of these intriguing phenomena. I will also briefly discuss our positron measurements on other wide band gap materials such ZnO and Y₃Al₅O₁₂ (YAG) and elucidate how we use PAS to tune their transport and optical properties.