ELECTRON PARAMAGNETIC AND NUCLEAR DOUBLE RESONANCE OF F+ CENTERS IN BEO SINGLE CRYSTALS

Single crystals of BeO which have been irradiated with neutrons show an EPR spectrum with partially resolved hyperfine structure. An ENDOR study of the hyperfine interaction leads to the conclusion that the spectrum arises from centers which consist of an electron trapped at an oxygen vacancy surrounded by four Be nuclei. The measured hyperfine interaction constants are: Ah=10.3 MHz, Ah=16.4 MHz, and (e2qQ)h=1.1 MHz for the Be nuclei not on the c axis; and Ah=4.2 MHz, Ah=9.2 MHz, and (e2qQ)h=1.5 MHz for the nuclei along the c axis. These values lead to |ψ(rBe)|2=0.13×1024 cm-3 for the electron wave function at the c-axis nuclei, and |ψ(rBe)|2=0.06×1024 cm-3 for the nonaxial nuclei. The measured g value for H parallel to the c axis is 2.0030. © 1969 The American Physical Society.