Studies of some physical properties of PrFe_0.7Ni_0.3O₃ thin films after 200 MeV Ag¹⁵⁺ irradiation

Abstract

PrFe_0.7Ni_0.3O₃ thin films (thickness ~ 200 nm) were prepared by pulsed laser ablation technique on LaAlO₃ substrate. These films were irradiated with 200 MeV Ag¹⁵⁺ ions at various fluencies, ranging from 1 × 10¹¹ to 1 × 10¹² ions/cm². These irradiated thin films were characterized by using X-ray diffraction, dc conductivity, dc magnetization and atomic force microscopy. These films exhibit orthorhombic structure and retain it even after irradiations. The crystallite size (110–137 nm), micro strain (1.48 × 10⁻²–1.75 × 10⁻² line⁻² m⁻⁴) and dislocation density (79.7 × 10¹⁴–53.2 × 10¹⁴ line/m²) vary with ion fluencies. An enhancement in resistivity at certain fluence and then a decrease in its value (0.22175–0.21813 Ω cm) are seen. A drastic change in observed magnetism after ion irradiation is seen. With ion irradiation, an increase in surface roughness, due to the formation of hillocks and other factors, is observed. Destruction of magnetic domains after irradiation can also be visualized with magnetic force microscopy and is in close agreement with magnetization data. The impact on various physical properties in these thin films after irradiation indicates a distortion in the lattice structure and consequently on single-particle band width caused by stress-induced defects.

Keywords:

• conductivity
• deposition
• electron irradiation

Acknowledgements

Author would like to thank Director IUAC, New Delhi, for providing beam time and other experimental facilities. Author would also like to thank Dr Ravi Kumar (Ex Scientist of IUAC New Delhi) for his valuable suggestions during this work. Author would also like to thank potential reviewers for their brilliant suggestions and comments to improve the quality of this write-up.