Effect of Y3+ substitution on the Magneto-Dielectric
properties of Lu3Fe5O12
P. Manimuthu, K. Ashok Kumar, V. G. Sree, C. Venkateswaran*
Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai- 600 025, India
author’s e-mail: cvunom@hotmail.com, Tel.: +91- 044–2220 2803; Fax: +91- 044-2235 3309
*Corresponding
Abstract
Polycrystalline Lu1.5Y1.5Fe5O12, has been prepared by
solid state reaction method. X-ray diffraction study
confirms the formation of cubic garnet phase.
Magnetization curve exhibits the ferrimagnetic behaviour
with saturation magnetization value of 21emu/g. Magnetodielectric measurement at room temperature shows a large
responds of 6% at an applied field of 1500 Oe.
Keywords: Rare-earth iron garnet, Solid state route,
Ferrimagnetic, Magneto-dielectric.
reported MS value of Y3Fe5O12 (24 emu/g [5]) is 6
emu/g greater than the reported value of Lu3Fe5O12.This
leads to the increase in magnetization value of
Lu1.5Y1.5Fe5O12 as observed in inset of Fig 2.
Introduction
Multiferroics attract a renewed interest due to the
spectacular discoveries of giant magneto-electric (ME)
and magneto-dielectric (MD) effects [1]. For the
utilization of these effects in multifunctional devices,
materials exhibiting low field ME or MD response are
essential. Hur et al [2] reported a relatively low
magnetic field (H < 2 kOe) MD effect in Tb 3Fe5O12 up
to 150 K. Still, application demands room temperature
magneto-dielectricity. Recently, Wu et al [3] reported
the room temperature (RT) MD response in Lu3Fe5O12.
In the present work, yttrium is chosen for substitution in
Lu3Fe5O12 because like Lu3+ in Lu3Fe5O12, Y3+ also has
no net magnetic moment. Since rare earth ions have
similar size, atomic mass, and in many cases, charge,
this ion distribution is not expected to vary much from a
rare-earth ion to another rare-earth ion. Hence, 50% of
yttrium is substituted at the dodecahedral site of
Lu3Fe5O12 to investigate the magneto-dielectric
properties.
Sample preparation
The raw powders of Lu2O3 (99.9 %), Fe2O3 (99.9 %)
and Y2O3 (99.9%) were directly mixed together
according to their stoichiometric proportion using an
agate mortar and pestle for 5 hours. The mixture was
kept in the furnace at 1173 K for about 2 h for
calcinations and then sintered at 1573 K for 5 h in air.
Results and discussion
Figure 1 shows the XRD pattern of Y3+ substituted
Lu3Fe5O12. The pattern was indexed on the basis of the
reflections from the JCPDS file No: 73-1375. Formation
of cubic garnet phase having a space group of Ia-3d is
evident. No peak belonging to Y2O3 was found in the
pattern, thus indicating the incorporation of Y3+ ion in
the garnet structure. Inset of Fig. 2 shows the
magnetization curve (M-H curve) of Lu1.5Y1.5Fe5O12
showing clear ferrimagnetic behavior at RT and
saturating at a low applied field of ~1500 Oe. The
saturation magnetization (Ms) value is determined to be
21emu/g which is greater than the MS value of
Lu3Fe5O12 (18 emu/g) [4]. This is due to the fact that
Fig. 1: XRD pattern of Lu1.5Y1.5Fe5O12.
Fig. 2: MD coupling at RT. Inset shows M-H plot.
Magneto-dielectric measurement was carried out in an
indigenously developed experimental setup [6]. The
magnitude of MD coupling changes with increasing
magnetic field suggesting strong coupling (Fig. 2). The
maximum coupling value of 6% at 103 Hz is observed
for the Y3+ substituted Lu3Fe5O12 sample, which is one
among the largest value for single phase material at
room temperature. Lu1.5Y1.5Fe5O12 has very good MD
response at room temperature even for a small applied
field, making it a good candidate explorable for
applications in magneto-dielectric devices.
Acknowledgment
Author PM thanks CSIR for the financial assistance through the
award of SRF.
References
[1] B. Lorenz et al., Phys. Rev. Lett. 92, 087204 (2004).
[2] N. Hur et al., Appl. Phys. Lett. 87, 042901 (2005).
[3] X. Wu et al, Appl. Phys. Lett. 95, 182903 (2009).
[4] P. Manimuthu et al, AIP Conference Proceedings 1447(1), 1205
(2012).
[5] D.T.T. Nguyet et al, J.Alloys and Compounds 541, 18 (2012).
[6] P. Manimuthu et al, Physica B: Condensed MatterDOI: 10.1016/j.physb.2014.03.051.