A. Yu. Mironovich, V. G. Kostishin, H. I. Al-Khafaji, A. V. Timofeev, E. S. Savchenko, A. I. Ril
{"title":"Submicron Barium Hexaferrite Ceramics Manufactured by Low-Temperature Liquid-Phase Sintering of BaFe12O19 Nanoparticles","authors":"A. Yu. Mironovich, V. G. Kostishin, H. I. Al-Khafaji, A. V. Timofeev, E. S. Savchenko, A. I. Ril","doi":"10.1134/S0036023624602630","DOIUrl":null,"url":null,"abstract":"<p>This work has solved the problem of manufacturing high-coercivity barium hexaferrite BaFe<sub>12</sub>O<sub>19</sub> ceramic samples. A BaFe<sub>12</sub>O<sub>19</sub> nanopowder with coercivity <i>H</i><sub>c</sub> = 445 kA/m was prepared by hydrothermal synthesis. Sintering was carried out at low temperature (900°C) to preserve the grains in a single-domain state. To perform sintering at such a low temperature, B<sub>2</sub>O<sub>3</sub> or Bi<sub>2</sub>O<sub>3</sub> was added to the hexaferrite. The effects of the amount and type of additive on the phase composition, microstructure, and magnetic properties of the sintered hexaferrite were studied. When Bi<sub>2</sub>O<sub>3</sub> (in the form of 0.5, 1, or 3 wt % of Bi(NO<sub>3</sub>)<sub>3</sub>) was used, no changes in the phase composition occurred, while addition of B<sub>2</sub>O<sub>3</sub> (in the form of 0.5, 1, or 3 wt % of H<sub>3</sub>BO<sub>3</sub>) resulted in a partial transformation of the hexaferrite to hematite α-Fe<sub>2</sub>O<sub>3</sub>. The average grain size of BaFe<sub>12</sub>O<sub>19</sub> increased in response to increasing Bi<sub>2</sub>O<sub>3</sub> or B<sub>2</sub>O<sub>3</sub> concentration, but did not exceed the critical single-domain size. This provided for the high <i>H</i><sub><i>c</i></sub> values (370–420 kA/m) of the sintered samples, making them superior to most well-known brands of unsubstituted hexaferrites.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"69 11","pages":"1637 - 1645"},"PeriodicalIF":1.8000,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Inorganic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1134/S0036023624602630","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
This work has solved the problem of manufacturing high-coercivity barium hexaferrite BaFe12O19 ceramic samples. A BaFe12O19 nanopowder with coercivity Hc = 445 kA/m was prepared by hydrothermal synthesis. Sintering was carried out at low temperature (900°C) to preserve the grains in a single-domain state. To perform sintering at such a low temperature, B2O3 or Bi2O3 was added to the hexaferrite. The effects of the amount and type of additive on the phase composition, microstructure, and magnetic properties of the sintered hexaferrite were studied. When Bi2O3 (in the form of 0.5, 1, or 3 wt % of Bi(NO3)3) was used, no changes in the phase composition occurred, while addition of B2O3 (in the form of 0.5, 1, or 3 wt % of H3BO3) resulted in a partial transformation of the hexaferrite to hematite α-Fe2O3. The average grain size of BaFe12O19 increased in response to increasing Bi2O3 or B2O3 concentration, but did not exceed the critical single-domain size. This provided for the high Hc values (370–420 kA/m) of the sintered samples, making them superior to most well-known brands of unsubstituted hexaferrites.
期刊介绍:
Russian Journal of Inorganic Chemistry is a monthly periodical that covers the following topics of research: the synthesis and properties of inorganic compounds, coordination compounds, physicochemical analysis of inorganic systems, theoretical inorganic chemistry, physical methods of investigation, chemistry of solutions, inorganic materials, and nanomaterials.