Swathi Chanda, S Bharadwaj, V R Reddy, Kirana Kommuri, Adiraj Srinivas, Y Kalyana Lakshmi
{"title":"An analysis of iron ion occupation in barium hexaferrites prepared employing different synthesis techniques from magnetic and Mossbauer studies","authors":"Swathi Chanda, S Bharadwaj, V R Reddy, Kirana Kommuri, Adiraj Srinivas, Y Kalyana Lakshmi","doi":"10.1007/s12034-023-03139-3","DOIUrl":null,"url":null,"abstract":"<p>In the present investigation, the distribution of iron ions at octahedral and tetrahedral sites in BaFe<sub>12</sub>O<sub>19</sub> prepared by employing four different synthesis techniques, namely, solid-state reaction, oxalate precursor route, sol–gel and wet chemical methods, have been examined using Mossbauer studies and compared with magnetization data. It was observed that the iron ions distribute in different preferential order at various sites for hexaferrites prepared using different synthesis methods, which is confirmed by Mossbauer spectroscopy. Prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Field emission scanning electron microscopy. Rietveld refinement of all samples revealed an M-type hexagonal structure confirming P63/mmc space group along with a minor peak belonging to the α-Fe<sub>2</sub>O<sub>3</sub> phase, except for the sample synthesized by sol–gel route. A uniform spherical shape with a small grain size was observed in sol–gel prepared samples and the Williamson–Hall method was adopted to estimate the average crystallite size, which varies between 72 and 129 nm. The room temperature magnetization studies reveal that the sample synthesized via sol–gel route shows high coercivity and saturation magnetization values due to their smaller grain sizes. Mossbauer spectra of all BaFe<sub>12</sub>O<sub>19</sub> samples were fitted with five sexets assigned to the hexagonal crystal structure of 4f<sub>2</sub>, 4f<sub>1</sub>, 2a, 12k and 2b sites, where the variation in their relative areas confirms the redistribution of iron ions at these sites.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Materials Science","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1007/s12034-023-03139-3","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
In the present investigation, the distribution of iron ions at octahedral and tetrahedral sites in BaFe12O19 prepared by employing four different synthesis techniques, namely, solid-state reaction, oxalate precursor route, sol–gel and wet chemical methods, have been examined using Mossbauer studies and compared with magnetization data. It was observed that the iron ions distribute in different preferential order at various sites for hexaferrites prepared using different synthesis methods, which is confirmed by Mossbauer spectroscopy. Prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Field emission scanning electron microscopy. Rietveld refinement of all samples revealed an M-type hexagonal structure confirming P63/mmc space group along with a minor peak belonging to the α-Fe2O3 phase, except for the sample synthesized by sol–gel route. A uniform spherical shape with a small grain size was observed in sol–gel prepared samples and the Williamson–Hall method was adopted to estimate the average crystallite size, which varies between 72 and 129 nm. The room temperature magnetization studies reveal that the sample synthesized via sol–gel route shows high coercivity and saturation magnetization values due to their smaller grain sizes. Mossbauer spectra of all BaFe12O19 samples were fitted with five sexets assigned to the hexagonal crystal structure of 4f2, 4f1, 2a, 12k and 2b sites, where the variation in their relative areas confirms the redistribution of iron ions at these sites.
期刊介绍:
The Bulletin of Materials Science is a bi-monthly journal being published by the Indian Academy of Sciences in collaboration with the Materials Research Society of India and the Indian National Science Academy. The journal publishes original research articles, review articles and rapid communications in all areas of materials science. The journal also publishes from time to time important Conference Symposia/ Proceedings which are of interest to materials scientists. It has an International Advisory Editorial Board and an Editorial Committee. The Bulletin accords high importance to the quality of articles published and to keep at a minimum the processing time of papers submitted for publication.