Dynamical Properties of Photo-Induced Spin Disorder in Half-Metal Systems |
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Authors: | A Nakamura XJ Liu K Matsuda Y Moritomo |
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Institution: | Center for Integrated Research in Science and Engineering and Department of Crystalline Materials Science , Nagoya University , Nagoya , 464-8603 , Japan |
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Abstract: | We have investigated critical relaxation phenomena of photoinduced spin-disorder and transient formation of charge-ordered states in R 0.6 Sr 0.4 MnO 3 (R = La, Nd 0.5 Sm 0.5 and Sm) and La 0.7 Ca 0.3 MnO 3 thin films by means of a pump-probe method. An absorption band at ¨ 1.5 eV is induced upon photo-irradiation, which suggests that CO clusters are transiently formed in the ferromagnetic state. In addition, it is found that the observed temperature variation of the relaxation time of photoinduced spin-disorder near the transition temperature is well interpreted in terms of the dynamical scaling theory based on a three-dimensional Heisenberg model for the second-order phase transition. |
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Keywords: | Manganite Magnetic Transition Critical Relaxation Phenomena Femtosecond Laser Spectroscopy |
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