Studies of some physical properties of PrFe_0.7Ni_0.3O₃thin films after 200 MeV Ag¹⁵⁺irradiation

PrFe0.7Ni0.3O3 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.