Associate Professor of Physics



Office: HAC424


Ph.D. in Condensed Matter Physics (2000), The University of Georgia under the direction of Uwe Happek

M.Ed. in Science Education (1998) The University of Georgia

B.S. in Physics (1993), The Georgia Institute of Technology


Optical and electrical properties of sol-gel produced metal oxides. Our group uses optical techniques to study the properties of impurity ion excited states in insulating materials. We are currently focusing in two areas: the interaction between excited lanthanide impurity states and luminescent quenching centers in sol-gel derived oxides, and the effects of sol-gel production parameters on the structure of ferroelectric materials.

See the Materials Physics Laboratory web site for more details.


Synthesis and spectral properties of Ce[Ag(CN)2]3, C.L. Larochelle and J.K. Krebs, Optical Materials 30: 1446-1450 (2008).

Decay dynamics of europium excited states in bioactive glasses, J.K. Krebs, *J.M. Brownstein, and *J.T. Gibides, Journal of Luminescence 128: 780-782 (2008).

Eu3+ site characterization in solution-grown yttrium oxide, J.K. Krebs and *C.M. Hobson, Materials Letters 61: 4134-4136 (2007)

Site-selective spectroscopy of Eu3+ in bioactive glass, J.K. Krebs and *J.M. Brownstein, Journal of Luminescence 124: 257-259 (2007)

Optical spectroscopy of trivalent chromium in sol-gel lithium niobate, J.K. Krebs and U. Happek, Applied Physics Letters 87 (25): Art. No. 251910 (DEC 19 2005)

Course Information

Teaching Interests

The use of a variety of teaching styles and activities to channel a large range of
students' interests into their study of physical principles.

Currently, I am studying the use of writing assignments to enhance students' understanding of physical principles.

My initial premise is that students who are able to recognize the structure of physical theories and describe their thoughts in an organized manner will demonstrate better problem solving skills.