Ultra-low magnetic damping of perovskite La_(0.7)Sr_(0.3)MnO_3 thin films

摘要

The perovskite La_(0.7)Sr_(0.3)MnO_3 (LSMO) films grown on different substrates were investigated by an angle resolved broadband ferromagnetic resonance technique. All films exhibited a four-fold magneto-crystalline anisotropy, which is in accord with the crystal structure. Moreover, a perpendicular uniaxial anisotropy changed from the (001)_(pc) easy plane to the [001]_(pc) easy direction when the strain of LSMO films varies from tensile to compressive. The ultra-low magnetic damping constant of 5.2 × 10~(-4) was obtained for a 44.6 nm LSMO film on an NdGa0_3 (110) substrate. The breathing Fermi surface model in which the damping constant is proportional to the density of states at Fermi energy is the dominant mechanism for the intrinsic magnetic relaxation.