Picosecond dynamics of the spin-lattice relaxation in La0.7Ca0.2MnO3: Magnetic-field dependence - art. no. 060410

摘要

We have employer ultrafast optical pump-probe measurements at 1.5 eV to study the picosecond dynamics of the magnetic-field-induced metal-insulator (MI) transition in La0.7Ca0.3MnO3 thin films in fields up to 7 T. We show that field induced modification of the photoinduced dynamic spectral weight transfer (DSWT) is related to changes in the magnetic entropy. The magnetic-field-induced increase of the ferromagnetic-paramagnetic transition temperature is evident in the spin-lattice relaxation time and amplitude scaling of the DSWT. [References: 12]