Double exchange between chromium ions in a KZnF3:Cr3+,Cr2+ crystal Eremin, M. V. ; Nikitin, S. I. ; Silkin, N. I. ; Tsvetkov, A. I. ; Yusupov, R. V. Abstract Publication: ZhETF Pisma Redaktsiiu Pub Date: April 1995 Bibcode: 1995ZhPmR..61..599E