Tuning the particle size, natural ferromagnetic resonance frequency and magnetic properties of ε-Fe2O3 nanoparticles prepared by a rapid sol–gel method. Issue 19 (26th April 2021)

• Record Type: Journal Article
• Authors: Gorbachev, Evgeny; Soshnikov, Miroslav; Wu, Mingxi; Alyabyeva, Liudmila; Myakishev, Dmitrii; Kozlyakova, Ekaterina; Lebedev, Vasilii; Anokhin, Evgeny; Gorshunov, Boris; Brylev, Oleg; Kazin, Pavel; Trusov, Lev
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 19(2021)
• Page Start: 6173
• Page End: 6179
• Publication Date: 2021-04-26
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc01242h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A fast method for the synthesis of ε-Fe2 O3, yielding 100% pure material with a variable FMR frequency, is proposed. Abstract : In this study, we demonstrate the synthesis and the investigation of magnetostatic and magnetodynamic properties of epsilon iron oxide (ε-Fe2 O3 ) nanoparticles of various sizes. Silica gels were obtained by rapid hydrolysis of tetraethoxysilane in an aqueous–alcoholic solution of iron(iii ) nitrate and then dried to form xerogels. The annealing of the xerogels at temperatures of 1000–1250 °C led to the formation of ε-Fe2 O3 particles with average sizes of 7–38 nm, respectively. With an increase in the annealing temperature, the coercivity of the samples increased and reached 21 kOe for 1200 °C, while the frequency of the natural ferromagnetic resonance increased from 161 to 170 GHz followed by narrowing of the absorption lines from 40 to 2 GHz. It was shown for the first time that the parameters of the natural ferromagnetic resonance line of epsilon iron oxide can be varied by controlling the size of ε-Fe2 O3 particles. It was also demonstrated that the duration of ε-Fe2 O3 synthesis can be considerably reduced by increasing the rate of tetraethoxysilane hydrolysis, while the magnetic properties of the target material do not degrade.