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conferenceseries
.com
Volume 6
Research & Reviews: Journal of Material Sciences
ISSN: 2321-6212
Magnetic Materials 2018
October 22-23, 2018
October 22-23, 2018 | Rome, Italy
3
rd
International Conference on
Magnetism and Magnetic Materials
Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C6-030
Synthesis and microwave characteristic of Y and Z type hexaferrite
Tatyana Koutzarova
1
, Svetoslav Kolev
1
, Borislava Georgieva
1
, Kiril Krezhov
1
, Daniela Kovacheva
2
, Chavdar Ghelev
1
, B. Vertruyen
3
, R Closset
3
, Lan
Maria Tran
4
and
Andrej Zaleski
4
1
Institute of Electronics, Bulgarian Academy of Sciences, Bulgaria
2
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Bulgaria
3
University of Liège, Liège, Belgium
4
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Poland
W
e report studies on the structural, magnetic and microwave properties and magnetic phase transitions of polycrystalline
Z-typeSr
3
Co
2
Fe
24
O
41
andY-typehexaferriteBa
0.5
Sr
1.5
Zn
2
Al
0.08
Fe
11.92
O
22
synthesizedby sol-gel auto-combustion.The results
of the ZFC and FC magnetization measurements of polycrystalline Z-type Sr
3
Co
2
Fe
24
O
41
show a change in the magnetization
behavior at 295 K, related to the magnetic phase transition from ferrimagnetic to transverse conical spin order. Therefore,
the magneto-electric effect can be observed below 295K. The Ba
0.5
Sr
1.5
Zn
2
Al
0.08
Fe
11.92
O
22
sample shows a triple loop at room
temperature, due to the presence of two kinds of ferrimagnetic states. The magnetization at 50 kOe was 47 emu/g. We observed
several magnetic phase transitions in the temperature ranging from 4.2 to 300 K for the Ba
0.5
Sr
1.5
Zn
2
Al
0.08
Fe
11.92
O
22
sample. The
magnetic phase transition from collinear ferromagnetic to proper-screw spin allows us to assume that Ba
0.5
Sr
1.5
Zn
2
Al
0.08
Fe
11.92
O
22
is a multiferroic below 285 K. The microwave properties of both the Z-type and Y-type hexaferrites were studied between 1-20
GHz. A polycrystalline sample of hexaferrite was dispersed in a polymer matrix. The reflection losses of the composite samples
were measured in an external magnetic field. A dramatic increase of the attenuation was observed due to the magnetic field
influence on the composite samples with Z-type powder as a filler.
tatyana_koutzarova@yahoo com