Publication Date:
2018-07-02
Description:
Publication date: September 2018 Source: Vacuum, Volume 155 Author(s): Ashish Ravalia, Bharat Kataria, Savan Katba, Sadaf Jethva, Megha Vagadia, K. Asokan, Sanjeev Gautam, Keun Hwa Chae, D.G. Kuberkar We report the effect of electronic excitations induced modifications in the ferroelectric polarization in BiFeO 3 (BFO) multiferroic films grown on 0.2% Nb doped SrTiO 3 (SNTO) substrates by pulsed laser deposition. The BFO/SNTO films were irradiated with 200 MeV Ag +15 ions with ion fluences of 5 × 10 10 to 5 × 10 12 ions/cm 2 and characterized by using X–ray diffraction (XRD), atomic force microscopy (AFM), ferroelectric polarization and near-edge X-ray absorption fine structure (NEXAFS) measurements. The XRD and AFM results show the creation of structural defects and oxygen vacancies by ion irradiation. Such defects induced enhancement in structural strain and reduction in mobility of charge carriers leading to the improvement in ferroelectric behaviour in BFO films. In addition, the local electronic structures investigated using NEXAFS studies reveal the significant change in spectral features suggesting the role of Bi-O and Fe-O hybridizations that modifies the ferroelectric behaviour of BFO films. These results are used to understand the mechanism.
Print ISSN:
0042-207X
Electronic ISSN:
1879-2715
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
