Suppression of ferromagnetic ordering in doped manganites Effects of the superexchange inte.pdfVIP

Suppression of ferromagnetic ordering in doped manganites: Effects of the superexchange interaction Hongsuk Yi Center for CMR Materials, Korea Research Institute of Standards and Science, Yusong, P.O. Box 102, Taejon 305-600, Korea 9 Jaejun Yu 9 Department of Physics and Center for Strongly Correlated Materials Research, 9 Seoul National University, Seoul 151-742, Korea 1 t Sung-Ik Lee c O National Creative Research Initiative Center for Superconductivity, Pohang University of Science and Technology, Pohang 790-784, Korea 1 (today) 1 ] From a Monte Carlo study of the ferromagnetic Kondo lattice model for doped manganites, including l e the antiferromagnetic superexchange interaction (JAF ), we found that the ferromagnetic ordering - was suppressed as J increased. The ferromagnetic transition temperature T , as obtained from a AF c r t mean field fit to the calculated susceptibilities, was found to decrease monotonically with increasing s. JAF . Further, the suppression in Tc scales with the bandwidth narrowing induced by the antiferro- t magnetic frustration originating from J