ESR Study of Pb³⁺ Ions in Cubic PbF₂ Crystals Irradiated with γ-Rays and Neutrons at Low Temperatures

Abstract

The ESR spectra of Pb 3+ ions in cubic PbF 2 crystals produced by irradiation with γ-rays and neutrons at low temperatures have been studied. Besides a large hyperfine structure from 207 Pb nucleus a complex superhyperfine structure due to the interactions with surrounding F and Pb nuclei is observed. From Breit-Rabi diagram the hyperfine splitting constant A ( 207 Pb) can be determined; its reduction with regard to the free ion value is discussed. From the measured angular dependence of the superhyperfine structure the principal values A (F) // , A (F) ⊥ and a ( 207 Pb) of the SHF-tensors are obtained. This induced ESR can be bleached thermally at around 175 K.