The Low-Temperature Magnetic State and Magnetic Ordering Temperature of ε-Fe2O3 Iron Oxide Nanoparticles
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
IEEE Magnetics Letters
ISSN: 1949-307X
, E-ISSN: 1949-3088
|
| Output data |
Year: 2019,
Volume: 10,
Article number
: 6110103,
Pages count
: 3
DOI:
10.1109/LMAG.2019.2956674
|
| Tags |
Fe2O3 nanoparticles; FMR spectra; magnetic transition |
| Authors |
Dubrovskiy Andrey A.
1
,
Semenov Sergey V.
1
,
Knyazev Yuri V.
1
,
Popkov Sergey I.
1
,
Yakushkin Stas S.
2
,
Kirillov Viktor L.
2
,
Martyanov Oleg N.
2
,
Balaev Dmitry A.
1
|
| Affiliations |
| 1 |
Kirensky Institute of Physics, Krasnoyarsk Scientific Center, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, 660036 Russia
|
| 2 |
Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia
|
|
Funding (1)
|
1
|
Russian Science Foundation
|
17-12-01111
|
The ϵ-Fe2O3 iron oxide polymorph is a well-known magnetic material with a complex magnetic structure, which undergoes a series of magnetic transitions in different temperature ranges. However, the ϵ-Fe2O3 phase diagram is still unclear. We report on the magnetic properties of a sample consisting of ϵ-Fe2O3 nanoparticles with an average size of 8 nm embedded in a SiO2 xerogel matrix without an admixture of foreign phases. Along with the features typical of the well-known ϵ-Fe2O3 magnetic transition in the temperature range 80–150 K, the temperature dependence of magnetization M ( T ) of ϵ-Fe 2 O 3 includes other low-temperature anomalies. In an external field of H = 70 kOe, there is a noticeable temperature hysteresis of magnetization at 50–90 K, and near T ≈ 50 K, the M ( T ) curves have a characteristic bending, which may be indicative of an additional magnetic transition. The ferromagnetic resonance spectra shows that, near 500 K, a magnetic phase transition occurs, which was previously thought to be a transition to the paramagnetic state. An analysis of the temperature dependence of the ferromagnetic resonance spectra shows that the magnetically ordered phase in ϵ-Fe2O3 exists up to about 800 K.