High-coercivity hexaferrite ceramics featuring sub-terahertz ferromagnetic resonance

Evgeny A Gorbachev; Lev A Trusov; Liudmila N Alyabyeva; Ilya V Roslyakov; Vasily A Lebedev; Ekaterina S Kozlyakova; Oxana V Magdysyuk; Alexey V Sobolev; Iana S Glazkova; Sergey A Beloshapkin; Boris P Gorshunov; Pavel E Kazin

doi:10.1039/d1mh01797g

High-coercivity hexaferrite ceramics featuring sub-terahertz ferromagnetic resonance

Mater Horiz. 2022 Apr 4;9(4):1264-1272. doi: 10.1039/d1mh01797g.

Authors

Evgeny A Gorbachev^{1

2

3}, Lev A Trusov^{2

3}, Liudmila N Alyabyeva⁴, Ilya V Roslyakov^{1

2

5}, Vasily A Lebedev⁶, Ekaterina S Kozlyakova⁷, Oxana V Magdysyuk⁸, Alexey V Sobolev², Iana S Glazkova², Sergey A Beloshapkin⁶, Boris P Gorshunov⁴, Pavel E Kazin²

Affiliations

¹ Department of Materials Science, Lomonosov Moscow State University, Moscow 119991, Russia.
² Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia. trusov@inorg.chem.msu.ru.
³ Department of Materials Science, MSU-BIT University, Shenzhen, Guangdong Province 517182, P. R. China.
⁴ Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia.
⁵ Kurnakov Institute of General and Inorganic Chemistry RAS, Moscow 119991, Russia.
⁶ Bernal Institute, University of Limerick, Limerick, V94 T9PX, Ireland.
⁷ Department of Physics, Lomonosov Moscow State University, Moscow 119991, Russia.
⁸ Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK.

PMID: 35112123
DOI: 10.1039/d1mh01797g

Abstract

Herein, we demonstrate for the first time compact ferrite ceramics with giant coercivity. The materials are manufactured via sintering single-domain Sr_0.67Ca_0.33Fe₈Al₄O₁₉ particles synthesized by a citrate-nitrate auto-combustion method. The obtained ceramics show coercivities up to 22.5 kOe and natural ferromagnetic resonance frequencies (NFMR) in a sub-THz range of 160-282 GHz. At a maximum density of 95%, the sample displays coercivity of 18.5 kOe, which is the highest value among dense ferrite materials reported so far. In addition, we report an unusual blueshift of the NFMR frequency from 160 to 200 GHz, which occurs during material sintering.