Modulation of ultrafast laser-induced magnetization precession in BiFeO 3 -coated La 0.67 Sr 0.33 MnO 3 thin films

The ultrafast laser-excited magnetization dynamics of ferromagnetic (FM) La 0.67 Sr 0.33 MnO 3 (LSMO) thin films with BiFeO 3 (BFO) coating layers grown by laser molecular beam epitaxy are investigated using the optical pump-probe technique. Uniform magnetization precessions are observed in the films under an applied external magnetic field by measuring the time-resolved magneto-optical Kerr effect. The magnetization precession frequencies of the LSMO thin films with the BFO coating layers are lower than those of uncoated LSMO films, which is attributed to the suppression of the anisotropy field induced by the exchange interaction at the interface between the antiferromagnetic order of BFO and the FM order of LSMO.