Title :
X-ray topographic study of vacuum swept quartz crystals [frequency standards application]
Author :
Zarka, A. ; Sebastian, M.T. ; Capelle, B.
Author_Institution :
Lab. de Mineral. et Cristallographie, Univ. Pierre et Marie Curie, Paris, France
Abstract :
The presence of an unusual X-ray topographic contrast in vacuum-swept α-quartz crystals, which disappears on prolonged X-irradiation, is reported. It is shown that electrodiffusion of impurity ions leads to the accumulation of negative charges near the anode side of the crystals. This results in a strained crystal lattice which gives a strong X-ray topographic contrast near the anode side of the crystal. During irradiation of such crystals the negative charges created are neutralized by the formation of Al-hole and Al-OH centers
Keywords :
OH--centres; V-centres; X-ray applications; X-ray crystallography; X-ray diffraction examination of materials; X-ray effects; crystal atomic structure of inorganic compounds; crystal resonators; frequency measurement; measurement standards; quartz; surface topography measurement; Al2O3; SiO2:Al,OH; X-ray crystallography; X-ray topographic contrast; electrodiffusion; impurity ions; irradiation; negative charges; strained crystal lattice; vacuum swept quartz crystals; Aluminum; Anodes; Cathodes; Crystals; Frequency; Impurities; Lattices; Oscillators; Production; Silicon;
Conference_Titel :
Frequency Control Symposium, 1988., Proceedings of the 42nd Annual
Conference_Location :
Baltimore, MD
DOI :
10.1109/FREQ.1988.27604
