Anomalously large changes in diffracted X-ray intensity from silicon single crystals produced by microwave fields

Results of a high resolution X-ray diffraction study of effects produced by microwave fields of frequency 2.45 GHz in silicon single crystals are reported. Microwaves travelled along a strip line evaporated along a diameter of the specimen crystal disc, which was aligned for diffraction from a desired set of lattice planes. Diffraction curves and high resolution traverse topographs were recorded and curvature measurements were made before, during and after application of the microwave field. An anamalously large increase in diffracted X-ray intensity from a large volume of the specimen was observed on application of the microwave field. The peak intensity in some cases increased by more than ten times. Integrated intensity also showed similar large changes. No significant change in the shape of the diffraction curves was observed upto microwave powers of ～10W. Some regions of the crystals showed a large decrease in intensity. High resolution traverse topographs directly showed the changes in intensity. Also, dot like defects were observed. Most of these changes were reversible. However, some irreversible effects were observed which suggest the possible use of this method in microwave field/power measurement as well as dosimetry. The observed effect could be due to influence of the field on the dispersion surface or due to strong interaction of the field with electron cloud of silicon atoms.