Dynamic Remagnetisation of CoFe2O4 Nanoparticles:Thermal Fluctuational Thawing of Anisotropy
Full article
| Common |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Journal of Physics D: Applied Physics
ISSN: 0022-3727
, E-ISSN: 1361-6463
|
| Output data |
Year: 2021,
Volume: 54,
Number: 27,
Article number
: 275003,
Pages count
: 11
DOI:
10.1088/1361-6463/abf371
|
| Tags |
cobalt ferrite; effective anisotropy; magnetodynamics; nanoparticles; superparamagnetism |
| Authors |
Balaev D A
1
,
Poperechny I S
2,3
,
Krasikov A A
1
,
Semenov S V
1
,
Popkov S I
1
,
Knyazev Y V
1
,
Kirillov V L
4
,
Yakushkin S S
4
,
Martyanov O N
4
,
Raikher Yu L
2
|
| Affiliations |
| 1 |
Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660000, Russia
|
| 2 |
Institute of Continuous Media Mechanics, Russian Academy of Sciences, Ural Branch, Perm 614068, Russia
|
| 3 |
Department of Phase Transitions Physics, Perm State National Research University, Perm 614990, Russia
|
| 4 |
Boreskov Institute of Catalysis, Russian Academy of Sciences, Siberian Branch, Novosibirsk 630090, Russia
|
|
Funding (2)
|
1
|
The Ministry of Education and Science of the Russian Federation
|
0356-2016-0403 (АААА-А17-117103050081-1)
|
|
2
|
Ministry of Science and Higher Education of the Russian Federation
|
075-00553-19-00 (АААА-А20-120020690030-5)
|
We report a study of the magnetodynamics of cobalt ferrite (CoFe2O4) nanoparticles with an average diameter of ~6 nm. Hysteresis loops were measured under quasi-static conditions and in pulse fields with amplitudes H0 of up to 130 kOe and for durations τP of 8 and 16 ms. The growth of coercivity Hc observed with an increase in the magnetic field variation rate dH/dt (determined by the values of H0 and τP) and the reduction of Hc with temperature is ascribed to the superparamagnetic effect. The proposed theoretical model explains the observed dependences fairly well. Notably, the effective magnetic anisotropy constant obtained exceeds the value for bulk crystals and might be indicative of the contribution of surface magnetic anisotropy.