Double exchange between chromium ions in the KZnF3:Cr 3+,Cr 2+ crystal

Abstract

In the optical spectrum of the KZnF 3 crystal doped with chromium ions, the absorption lines of Cr 2+-Cr 3+ ion pairs with dynamic electron transfer between chromium ions via the intermediate fluorine ion (double 180 degree exchange) are observed. The value of the transfer integral for the e g-electron was directly measured for the first time using the temperature dependence of the integral intensity of the absorption lines.