Anisotropic electrical properties of 200 MeV Ag+15 ion irradiated manganite films

Abstract

In the present communication, the investigations on the structural, morphological, electrical and magnetodielectric (MD) properties of pulsed laser deposited La0.90Ca0.10MnO3 (LCMO) nanostructured thin films grown on SNTO substrate followed by irradiation using 200 MeV Ag+15 ions have been carried out. Structural properties were studied using X–ray diffraction (XRD) technique. The lattice mismatch was calculated from the XRD spectra in order to get insights on the interfacial strain in all the thin films. Morphological properties were determined using atomic force microscopy (AFM) to study the irradiation induced alterations in the LCMO nanostructured thin films. Dielectric spectroscopy as a function of frequency was carried out to study the electrical properties of pristine and irradiated samples. The anisotropic MD properties were measured by employing the external magnetic field of 1 T in two different geometries, i.e. magnetic field perpendicular and parallel to the samples' plane. Various theoretical models such as relaxation time and universal dielectric response model were employed to explain the mechanisms governing the electrical properties. The ac conductivity and impedance were also measured under the presence of external magnetic field and compared with the measurements carried out in the absence of the magnetic field. The measured ac conductivity was modeled using Jonscher's power law which signified the conduction mechanism in the presently studied samples.