Strain Broadening of E.P.R. Linewidths in Fe/Mgo Single Crystals and Powders

Abstract

The E.P.R. linewidth of the M= + 1/2 <-» -1/2 transition of Fe3+ spectrum of Fe/MgO single crystals and powders have been measured at 9 GHz before and after annealing. The nominal iron concentrations ranged from 310 to 11900 p.p.m. Specimens were annealed at 500°C up to 24 hours. For single crystal, anneal¬ing produced reductions in peak-to-peak linewidth (AHpp) which occurred in two stages for all the spec¬imens examined. The values of the first and second decay rates were found to be concentration dependent. For powdered single crystal, annealing produced an increase in the peak-to-peak linewidth (AHpp).