Temperature dependent Sign Reversal of Exchange
Bias in YbCrO3
Preeti Gupta and Pankaj Poddar*
Physical & Material Chemistry Division, CSIR-National Chemical Laboratory, Pune –411008, India, 2Academy of
Scientific and Innovative Research, Anusandhan Bhawan, 2 Rafi Marg, New Delhi-110 001, 3Center of Excellence
on Surface Science, CSIR-National Chemical Laboratory, Pune – 411008, India
Email: p.poddar@ncl.res.in
further confirm the exchange bias behavior of YCO
Abstract
We report an existence of giant, temperature-dependent
polycrystallites, training effect was done which shows
negative-magnetization (magnetization-reversal) behavior in
decrease in exchange bias field with increasing number
the YbCrO3 (YCO) polycrystallites. In addition, we also report
of measurement cycle. Detailed analysis of
a temperature-dependent sign-reversal in exchange-bias,
magnetization has been done.
1
which vanishes above Néel temperature.
Results and Discussion:
Powder samples of ytterbium chromite were
synthesized using hydrolytic sol-gel method and were
used for further characterization. The temperature
dependence of ZFC and FC magnetization curves
(fig.1(a)) at 100 Oe for YCO polycrystallites shows a
Nèel transition at (TN) ~119 K and NM was also
observed just below TN which become positive at 19 K.
M-H curves at 200 K and below show positive
exchange bias which switches to negative at 14 K. The
field cooled M-H curve at 60 K shows switching of
exchange bias field from positive to negative at ±1T. To
0.10
0.00
-0.03
0.05
0
Tcross=13 K
0.1 (b)
Moment (emu/g)
Tcross=13 K
TN=119 K
Temperature (K)
50 100 150 200 250
TN=119 K
0.00
200 K
100 K
80 K
60 K
40 K
20 K
14 K
10 K
7K
5K
0.0
-0.1
-0.05
0
(c)
50
100 150 200
Temperature (K)
T=60 K
1
250
300
-2
1T
-1 T
0
Magnetic field (kOe)
390 (d)
HEB
HC
386
384
382
0.00
-0.03
-1
-5
0
5
Magnetic field (kOe)
10
0n
1n
2n
3n
4n
108.0
Magnetic field (kOe)
380
-10
109.2
108.6
0.03
Moment (emu/g)
HEB (Oe)
388
0
2
Hc (Oe)
dMFC/dt (emu/g K)
100 Oe
0.03
Moment (emu/g)
Introduction
Rare earth chromites have attracted
considerable attention in past owning to its magnetic
phases at low temperature and existence of
ferroelectricity in this class of materials.1,2 Negative
magnetization (NM) and exchange bias (EB) effects
continue to draw attention due to their potential
application in magnetic read heads, magnetic random
access memories and other spintronic devices.3,4
YbCrO3, owning to its strong anisotropic exchange
interaction between the Cr3+ and Yb3+ ions gives
various kinds of complex magnetic behaviour.5 YbCrO3
crystallizes in a distorted orthorhombic perovskite
structure with Pbnm space group and Cr3+ spins order
antiferromagnetically at at ~119 K.5 In this work, we
have investigated the structural and magnetic properties
of YbCrO3 polycrystallites. Here, we tried to explain the
behavior of NM in YCO by field dependent dcmagnetic studies. We also present training and
temperature dependent EB effect on YCO
polycrystallites.
(a)
0.15
Moment (emu/g)
Keywords: multiferroics, exchange-bias, negativemagnetization, rare earth chromite etc.
-2 -1 0
0
1
2
1
2
3
no. of cycles (n)
4
Fig. 1(a) ZFC-FC magnetization curve (b) isothermal
hysteresis curve at different temperature (c) field cooled
curve at 60 K with applied field ±1T (d) training effect
of YCO polycrystallites.
Acknowledgment
P.G acknowledges the support from the Council of
Scientific and Industrial Research (CSIR), India for
providing Senior Research Fellowship (SRF).
References
[1] K. Tsushima, K. Aoyagi, and S.Sugano, J. Appl.
Phys. 41, 1238 (1970).
[2] K. Sardar, M. R. Lees, R. J. Kashtiban, J. Sloan,
and R. I. Walton, Chem. Mater. 23, 48 (2011).
[3] J. Nogues and I. K. Schuller, J. Magn. Magn.
Mater. 192, 203 (1999).
[4] P. Gupta, R. Bhargava, R. Das and P. Poddar, RSC
Adv.3, 26427 (2013).
[5] Yuling Su, Jincang Zhang, Zhenjie Feng, Li Li,
Beizhan Li, Yun Zhou,Zhenping Chen, and Shixun Cao,
J. Appl.Phys.108, 013905, 2010.