Preparation and study of silver added La0.67Ca 0.33MnO3 film

Abstract

La0.67Ca0.33MnO3 (LCMO) and Ag admixed La0.67Ca0.33MnO3 (Ag-LCMO) polycrystalline films have been prepared on SrTiO3 single crystal (100) substrates by ultrasonic spray pyrolysis technique. These films are characterized using XRD, SEM, and temperature dependence of resistivity (ρ-T) and ac susceptibility (χ-T). The films are having cubic structure with lattice parameters as 3.890 and 3.885Å for LCMO and Ag-LCMO films, respectively. The peek in ρ-T curve (Tp) and the ferromagnetic transition temperature (TC) for the Ag-LCMO film is higher than that of LCMO film. The stability of both the films was tested by repeated measurements of its characteristics over a period of one week after several thermal cycling from room temperature to 77 K. In the LCMO film, the peak in the ρ-T curve (Tp) is found to shift towards lower value and conduction noise of the film increases in the subsequent measurements. In the case of Ag-LCMO the value of Tp, TC and conduction noise of the film did not change even after several measurements. Silver segregating at the grain boundaries in Ag-LCMO polycrystalline film seems to be responsible for improving the characteristics of Ag-LCMO films. © 2003 Elsevier Ltd. All rights reserved.