Swift-heavy-ion-irradiation-induced enhancement in electrical conductivity of chemical solution deposited La0.7Ba0.3MnO3 thin films

TL;DR

This study demonstrates that swift heavy-ion irradiation significantly improves the electrical conductivity of La0.7Ba0.3MnO3 thin films by enhancing crystallinity and grain connectivity, leading to reduced resistivity and modified magnetoresistance.

Contribution

It is the first to show how swift heavy-ion irradiation enhances conductivity and magnetoresistance in chemical solution deposited manganite thin films.

Findings

Resistivity decreased by factors of 3 and 10 at 330 K and 10 K respectively.

Irradiation improved film crystallinity and grain connectivity.

Magnetoresistance increased near the insulator-metal transition after irradiation.

Abstract

Epitaxial thin films of La0.7Ba0.3MnO3 manganite, deposited using Chemical Solution Deposition technique, were irradiated by 200 MeV Ag+15 ions with a maximum ion dose up to 1x10^12 ions/cm2. Temperature- and magnetic field-dependent resistivity measurements on all the films (before and after irradiation) reveal a sustained decrease in resistivity with increasing ion dose. A maximum dose of 1x10^12 ions/cm2 suppresses resistivity by factors of 3 and 10, at 330 K [insulator-metal (I-M) transition] and at 10 K, respectively. On the other hand, with increasing ion dose, the magnetoresistance (MR) enhances in the vicinity of I-M transition but decreases at low temperatures. These results, corroborated by surface morphology of films, suggest that the origin of such properties lies in the irradiation induced improved crystallinity and epitaxial orientation, enhanced connectivity between grains, and conglomeration of grains which result in better conductivity at grain boundaries.