Anomalous Behavior of Electron Spin Resonance in K_xC₆₀ Film Prepared by Electrochemical Method

Abstract

Single crystals doped with the electron trap Pd2-and a small concentration of Fe2were irradiated with ultraviolet light to produce the trigonal and the cubically symmetric ferric centres. These consist of an interstitial Fe3' bound to either three or four cation vacancies, respectively. Evidence is presented that the capture of a hole by Fe2' at low temperature results in the ejection of a neighbouring cation into a more distant interstitial site, and that this process involves an activation energy barrier. The ranges of temperature for efficient production of the two types of ferric centre in AgCl were found to correlate well with the trapping and detrapping of photocarriers at other sites, and with the temperature dependence of the jump frequency of the cation vacancy.