Annealing effect on the structure and electronic transport properties in La5/8Ca3/8MnO3/ErMnO3 multilayer thin films

Ferromagnetic La5/8Ca3/8MnO3 (LCMO) and Ferroelectric ErMnO3 (EMO) multilayer thin films with sandwich structure (LCMO/EMO/LCMO) were grown on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] substrates by pulsed laser deposition (PLD) method. For these films, the structural characterization was carried out by X-ray diffraction (XRD), and the temperature-dependence resistivity (p-T) showing the metal-insulator transition (Tp) also was measured. In the multilayer thin films the LCMO (002) peak move to lower Bragg angles after annealing at 900 degrees C for 30 hours under 1atm Oxygen pressure, and this condition is much different from the LCMO single layer films where the (002) peak moves to higher Bragg angle after annealing due to the lattice mismatch between the LCMO layer and the substrate. By increasing the thickness of LCMO, the multilayer samples show two MR peaks in a wide temperature range during the process of M-l transition. This phenomenon is attributed to a new (La5/8Ca3/8)xEr(1-x)MnO3 layer produced by the solubility between LCMO and EMO layers after high-temperature annealing. In this paper, we provide some evidence of dissolution between LCMO and EMO layers, and discuss the influence on structure and electronic transport properties in the composite thin films by annealing.