||January 1, 2008
||C.J. Bonifas, A.M. Marconnet, J. Perry, J.H. Booske, and R.F. Cooper,
||Journal of Microwave Power and Electromagnetic Energy
||Link to Full Text
Journal of Microwave Power and Electromagnetic Energy, vol. 42, pp. 13-22, 2008.
Experiments were conducted to compare the annealing of nano-porous aluminum oxide membranes by 2.45 GHz microwave radiation and by conventional (resistive element) furnace heating. The starting material was , membranes that were 60μm thick, 13mm in diameter, and containing pores of approximately 200nm diameter. Changes in the porosity and morphology were recorded from digital processing of scanning electron microscope (SEM) images. The data indicates that both microwave and conventionally-heated annealing resulted in a decrease of surface porosity and an apparent increase in the number of pores. However, microwave annealing consistently resulted in a 4-5% greater reduction in porosity and a greater increase in the number of (small) pores than conventionally-heated annealing. These results are consistent with a nonthermal mechanism for microwave-enhanced surface diffusion, although the complex morphology of the pores precluded a quantitative theoretical analysis.