Magnetic exchange interactions in cerium compounds

Exchange interactions induced by hybridization of $f$ levels to conduction-electron states in some Ce compounds are considered in detail. The usual treatment in which these interactions are derived through a second-order canonical transformation does not include all contributions. Using a free-electron conduction band, closed expressions are obtained for the range function, which approaches the Ruderman-Kittel-Kasuya-Yosida (RKKY) function asymptotically. For nearest and next-nearest neighbors the interactions are dominated by a new range function which differs from the RKKY function.