X-ray electret state in bismuth silicon oxide

Several important characteristics of the electret in single crystals of bismuth silicon oxide (Bi12 SiO20) formed under X-ray irradiation in the presence of an external polarizing electric field have been studied in this work. The following characteristics have been examined: dependence of the electret charge on the polarization time, dark depolarization of the electret, a check on the reciprocity law. The results obtained have been compared with the corresponding characteristics of the photoelectret state in the same crystal. It is shown that some peculiarities arise when X-rays are used in the polarization process. (authors)