Journal of Materials Science

, Volume 32, Issue 5, pp 1347–1355 | Cite as

Enhanced diffusion in sapphire during microwave heating

  • W. R ALLEN


The diffusion of oxygen in sapphire was accelerated by heating in a 28 GHz microwave furnace as compared with heating in a conventional furnace. Tracer diffusion experiments were conducted using 18O. Single crystal sapphire wafers with a (1 0 1 2) rhombohedral planar orientation were used as the substrate. Concentration depth profiling was done by proton activation analysis using a 5 MeV Van de Graaff accelerator. The diffusion of 18O was greatly enhanced by microwave heating as compared with conventional heating in the 1500–1800°C range. The apparent activation energy for 18O bulk diffusion was determined to be 390 kJ mol-1 with microwave heating and 650 kJ mol-1 with conventional heating.


Microwave Sapphire Silicon Nitride Apparent Activation Energy Microwave Heating 


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Copyright information

© Chapman and Hall 1997

Authors and Affiliations

    • 1
  • W. R ALLEN
  1. 1.Metals and Ceramics DivisionOak Ridge National LaboratoryOak RidgeUSA

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