Kumar, Hemaunt Singh, Jitendra Pal Srivastava, R. C. Negi, P. Agrawal, H. M. Asokan, Kandasami Won, Sung Ok Chae, Keun Hwa 2024-01-20T06:01:39Z 2024-01-20T06:01:39Z 2021-09-05 2015-10-05 0925-8388 https://pubs.kist.re.kr/handle/201004/124902 Present work investigates electronic excitation induced cationic exchange phenomena in nano-sized cobalt ferrites using Mossabaur and X-ray absorption spectroscopies. The electronic excitations were produced by irradiation of 100 MeV O+7 at different fluences ranging from 1 x 10(11) to 1 x 10(14) ions/cm(2). Cubic spinel phase of cobalt ferrite remains preserved after irradiation. However, attributes of crystalline disorder were observed in irradiated materials. Crystallite size remain almost same for pristine and irradiated materials. X-ray absorption fine structure measurements show the preservation of valence state and spin state of metal ions under intense electronic excitation. These measurements also envisage bond breaking process induced by the electronic excitation. Mossbauer spectroscopic measurements also corroborate with the fine structure measurements that the valence state of Fe remains same after irradiation. Paramagnetic doublet which presents in the Mossabaur spectrum of pristine material disappears after irradiation, showing the evolution of irradiation induced magnetic ordering. Fe3+ ion increases with irradiation at octahedral site of spinel lattice. Magnetization of the material slightly increases after irradiation at the fluence of 5 x 10(13) and 1 x 10(14) ions/cm(2). (C) 2015 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE SA MAGNETIC TUNNEL-JUNCTIONS ZINC FERRITE ELECTRICAL-PROPERTIES RAMAN-SPECTROSCOPY NANOSTRUCTURES IRRADIATION MOSSBAUER NANOPARTICLES Onset of size independent cationic exchange in nano-sized CoFe2O4 induced by electronic excitation Article 10.1016/j.jallcom.2015.04.227 1 JOURNAL OF ALLOYS AND COMPOUNDS, v.645, pp.274 - 282 JOURNAL OF ALLOYS AND COMPOUNDS 645 274 282 scie scopus 000357146300041 2-s2.0-84929431169 Chemistry, Physical Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Chemistry Materials Science Metallurgy & Metallurgical Engineering Article MAGNETIC TUNNEL-JUNCTIONS ZINC FERRITE ELECTRICAL-PROPERTIES RAMAN-SPECTROSCOPY NANOSTRUCTURES IRRADIATION MOSSBAUER NANOPARTICLES Electronic excitation Crystalline disorder Valence state