Abstract: | The structure, orientation, and the response of electroresistance to magnetic field H and varying temperature T have been studied for 30-nm-thick La0.67Ba0.33MnO3 (LBMO) films. The deviation of the 001] direction in manganite layers from the normal to the plane of the (LaAlO3)0.29 + (SrAl0.5Ta0.5O3)0.71 substrate strictly corresponds to the vicinal angle of the latter. The minimum yield determined from 227-keV proton scattering
spectra is 0.025, signifying a high order of the cationic sublattice in the films. The biaxial compression of stable nuclei
of the manganite phase affects their stoichiometry, thus contributing to the depletion of LBMO films in the alkaline-earth
element. The maximum electroresistance values have been observed in the films grown at T
max ≈ 320 K, a temperature about 20 K lower than the Curie temperature of the corresponding bulk single crystals, and the maximum
magnetoresistance (MR ≈ −0.42, μ0
H = 2 T) occurs at T ≈ 300 K. At low temperatures (T < T
max/3) and μ0
H < 0.45 T, the electroresistance response of LBMO films to a magnetic field materially depends on the anisotropic magnetoresistance
and the intensity of hole scattering from domain walls; when μ0
H > 0.5 T, the major current-carrier relaxation mechanism is the interaction with magnons. |