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Synthesis and Magnetic properties of SmFeMnO5
N. Aparnadevi, K. Saravana Kumar, A. Muthukumaran, and C. Venkateswaran*
Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025. India.
*Corresponding author’s e-mail: [email protected]
Abstract: SmFeMnO5 is obtained by high-energy ball milling of stoichiometric oxide precursors, followed by
sintering at 950 ĚŠ C for 12 h. The crystal structure is orthorhombic with Pbam space group as revealed by Rietveld
analysis of X-ray diffraction data. Room temperature magnetization study show a ferromagnetic hysteresis loop
with a saturation magnetization of 6.27 emu/g.
Keywords: Mechanical Milling; Multiferroic; Frustrated Magnets; Rietveld; Ferromagnetic
INTRODUCTION
SmMn2O5 is a magnetoelectric material having
frustrated geometry in their magnetic lattice. The mixed
oxidation state of Mn ions (Mn3+, Mn4+) determine their
magnetic behaviour through superexchange interaction,
inducing unique ferroelectric phases [1]. The magnetic
spin ordering in SmMn2O5 can be altered by the
substitution of Fe3+ ions in Mn3+ sites.. The effect of Fe
in SmMn2O5 is not yet reported.
EXPERIMENTAL
Polycrystalline powder of SmFeMnO5 is
obtained from high energy ball milling of the precursor
oxides, followed by sintering at high temperatures.
polyhedra, in addition to the decrease in the effect of Jahn
Teller Mn3+ ion resulting in alteration of bond angles and
distances and changing magnetic properties.
A narrow hysteresis loop, characteristic of
ferromagnetic material is obtained from RT VSM
measurement as shown in Fig. 2. The saturation
magnetization (MS) is 6.57 emu/g at a maximum applied
field of 15 kOe. The remanent magnetization (MR) and
coercivity (HC) are 2.81 emu/g and 222 Oe, respectively
with the ratio MR/MS of 0.43. The contribution from the
secondary phase SmMnO3 is absent due to its
paramagnetic nature whereas the ferrimagnetic Fe3O4 has
a saturation magnetization of 92 emu/g [3].
Fig. 2. Magnetization curve of SmFeMnO5.
Fig. 1.Rietveld refinement of SmFeMnO5 X-ray
diffraction pattern.
RESULTS AND DISCUSSION
The unit cell parameters of SmFeMnO5 are
found to be a=7.4358(1) Å, b=8.5856(2) Å, and c=5.6944
(1) Å with a volume 363 Å3, from Rietveld refinement of
the X-ray diffraction data, as shown in Fig. 1. Refinement
is carried out using FULLPROF, with the assumption
that Fe3+ ions replace the Mn3+ sites in parent SmMn2O5.
Secondary peaks related to SmMnO3 and Fe3O4 were also
identified. Formation of SmMnO3 phase, may be related
to the size of the Sm3+ cations [2]. In SmMnFeO5,
substitution of Fe3+ at Mn3+ sites affect the size of the
ACKNOWLEDGEMENTS
KSK acknowledges DRDO, India for support
through fellowship. NAD acknowledges Sampathu for
his kind help.
REFERENCES
[1] S.W. Cheong, Multiferroics: a magnetic twist for
ferroelectricity, Nature materials, 6, 1, 13-20 (2007).
[2] J. A. Alonso et al., Moderate-pressure synthesis and
neutron diffraction study of new metastable oxides, Z.
Naturforsch, 61b, 1507-1514 (2006).
[3] X. Yang et al., Superparamagnetic graphene oxideFe3O4 nanoparticles hybrid for controlled targeted drug
carriers, J. Mat. Chem., 19, 2710-2714 (2009).
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