Abstract
Two different paramagnetic centres of a similar nature are studied by EPR. in CaS polycrystals plastically deformed at 300 K after annealing at 575 to 825 K and subsequent X-raying of the samples at room temperature. These centres arise most likely from cation-anion vacancy pairs after an electron is captured at the anion vacancy. The electron is released in different temperature ranges if the cation and anion vacancies are either the nearest (nn) neighbours (365 to 515 K), or the next nearest (nnn) neighbours (475 to 625 K) in the CaS lattice. Both vacancy pairs are formed when migrating cation vacancies are captured by anion vacancies at annealing in the range of temperatures 575 to 675 K. (nnn) vacancy pairs are transformed into (nn) pairs at 675 to 725 K, while both complexes decrease in number and disappear at 725 to 825 K.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have