Effect of Bi3+ on magnetic properties of nanosized La0.7-xBixSr0.3MnO3

Nanoparticles of La0.7-xBixSr0.3MnO3 (0 < x < 0.40) manganites, prepared by high energy planetary ball mill using the top-down approach, have been subjected to structural and magnetization studies to understand the influence of Bi3+ substitution. In the present work, we compare the properties of nanoparticles of all compositions prepared by milling up to 48 h. The structural analysis carried out on the X-ray diffractograms using Rietveld refinement method suggest that as Bi3+ content increases, the structure changes from rhombohedral (space group R-3c, in hexagonal setting) for x < 0.20 to orthorhombic (space group Pnma) for x > 0.30. We also find that the particle size of ti 17 nm observed in x = 0.0 sample, increases to ti 40 nm for x = 0.35 sample. It is interesting to note that along with changes in the structure and particle size, we observe a cross-over from ferromagnetism (FM) in x = 0.0 (TC = 370 K) to antiferromagnetism (AFM, for x > 0.40). With increase in Bi3+, FM decreases and AFM evolves in the system. For x = 0.40, no long-range ferromagnetism has been noticed. The observed changes in the structural and physical properties could be attributed to the 6 s lone pair character of Bi3+ ions. In the present work, details of structural analysis and magnetization measurements will be presented and discussed. (c) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Recent Advancements in Materials science And Nanotechnology conference.