J Supercond Nov Magn
DOI 10.1007/s10948-017-4170-x
ORIGINAL PAPER
M¨ ossbauer Analysis and Cation Distribution of Zn
Substituted BaFe
12
O
19
Hexaferrites
I. A. Auwal
1
· A. D. Korkmaz
2
· M. D. Amir
3
· S. M. Asiri
4
· A. Baykal
4
·
H. G ¨ ung ¨ unes ¸
5
· S. E. Shirstah
6
Received: 13 May 2017 / Accepted: 16 May 2017
© Springer Science+Business Media New York 2017
Abstract Barium hexaferrite is a well-known hard mag-
netic material. Doping using nonmagnetic cation such as
Zn
2+
were found to enhance magnetization owing to prefer-
ential tetrahedral site (4f
1
) occupancy of the zinc. However,
the distribution of cations in hexaferrites depends on many
factors such as the method of preparation, nature of the
cation, and chemical composition. Here, Zn-doped bar-
ium hexaferrites (Ba
1−x
Zn
x
Fe
12
O
19
) were synthesized by
sol-gel method. In this study, we summarized the mag-
netic properties of Ba
1−x
Zn
x
Fe
12
O
19
(x = 0, 0.1, 0.2,
0.3) BaM, investigated by M¨ ossbauer spectroscopy. More-
over, cation distribution was also calculated for all the
products. M¨ ossbauer parameters were determined from
57Fe M¨ ossbauer spectroscopy and according to it, the
A. Baykal
abaykal@uod.edu.sa
1
Department of Chemistry, Sule Lamido University,
Kafin Hausa, Jigawa State, Nigeria
2
Department of Chemistry, Faculty of Engineering
and Natural Science, Istanbul Medeniyet University,
34700 Uskudar, Istanbul, Turkey
3
Department of Chemistry, Faculty of Engineering,
Istanbul University, 34320 Avcilar, Istanbul, Turkey
4
Department of Nano-Medicine Research, Institute
for Research and Medical Consultations (IRMC), University
of Dammam, P.O. Box 1982, Dammam 31441, Saudi Arabia
5
Department of Physics, Hitit University, 19030 C ¸ evre Yolu
Bulvarı-C ¸ orum, Turkey
6
Spin Device Technology Center, Faculty of Engineering,
Shinshu University, Nagano 380-8553, Japan
replacement of Ba-Zn affects all parameters such as isomer
shift, the variation in line width, hyperfine magnetic field,
and quadrupole splitting. Cation distribution revealed the
relative area of undoped BaM, 12k,2a, and 4f
2
positions
which are close to theoretical values.
Keywords Hexaferrites · Superparamagnetism · Hyperfine
interactions · Cation distribution
1 Introduction
The peroxdure or simply M-type hexagonal ferrites
(Ba/SrFe
12
O
19
), with magnetoplumbite structure, are gen-
erally regarded as hard ferrites, due to their wide range
of applications from permanent magnetic materials to
microwave. Their intrinsic magnetic character is associ-
ated with their crystal structure and magnetocrystalline
anisotropy along their c-axis [1]. These materials are well
known for their high resistivity, high magnetization per
formula unit, high Curie temperature, large magnetic–
dielectric loss, and low processing cost. They also found
numerous technological applications like radar absorbing
materials (RAMs), magnetic recording, channel filters, sen-
sors, tuning slugs, sound systems, microwave gyromagnetic,
and electronic devices [2–7].
The crystal structure of M-type hexaferrite composes of
a unit cell which is the sum of two molecular M units which
made up of 64 ions (32 per molecular unit). Each molecu-
lar unit possess two kinds of blocks which are hexagonal R
and cubical S in a serial order of SRS
∗
R
∗
(where S
∗
and R
∗
blocks are rotated around the axial through an angle of 180
◦
)
overlapping one another. Out of 64 ions, 38 are of O
2−
ions
and 24 are of Fe
3+
ions which disposed over five symmetry
sites, 1 tetrahedral (4f
1
), 1 trigonal bipyramidal (2b), and