Impurity Effect on Ferromagnetic Transition in Double-Exchange Systems

Abstract

Effect of randomness in the double-exchange model is studied. Large fluctuations and spatial random distribution of impurities are taken into account in an essentially exact manner by using the Monte Carlo calculation. The randomness suppresses the ferromagnetism by reducing the coherence of itinerant electrons. The suppression is significant in the critical region where the fluctuations are dominant. Temperature dependences of the magnetization are estimated for finite-size clusters. A characteristic temperature for phase transition $T^{\ast }$ is estimated from the inflection point, which is expected to give a good approximation for the critical temperature in the thermodynamic limit. Our results suggest that the ferromagnetism becomes unstable more rapidly than predicted in the previous theoretical results by the coherent-potential approximation.

7 pages including 4 figures, submitted to Proc. ISSP8

References in corpus (2)

• Critical Phenomena of Ferromagnetic Transition in Double-Exchange Systems
• Non-equilibrium Relaxation Study of Ferromagnetic Transition in Double-Exchange Systems

Cited by in corpus (4)

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• Inhomogeneous Ferromagnetism and Unconventional Charge Dynamics in Disordered Double Exchange Magnets
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