Transport and magnetic properties of DC-magnetron sputterred Ln0.7Mn1.3O3−δ thin films

Abstract Epitaxial thin films of Ln 0.7 Mn 1.3 O 3− δ have been grown on [0 0 1]-oriented LaSrAlO 4 substrates by DC-magnetron deposition. Magnetization, resistivity, thermopower, and magnetic resonance spectra are investigated over a range of temperatures and magnetic fields. The magnetic polaron theory is used, phenomenologically, to provide a quantitative explanation of transport properties of the oxidized films both above and below Curie temperature T C . The main assumption is that metal–insulator transition near T C is due to a crossover in polaronic mobility. At low temperatures we observe an anisotropy of magnetic resonance spectra, both resonance field and linewidth. To qualitatively account for all the observations (resistivity, thermopower, and magnetic resonance spectra) we suggest an intrinsic electric and magnetic inhomogeneity of the samples.