Investigation of the magnetic property of Gd doped
TiO2 nanoparticles
Susmita Paul*, Gazi Ameen Ahmed, Amarjyoti Choudhury.
Department of Physics, Tezpur University, Napaam, Assam-784028, India
Corresponding author’s e-mail:spspaul423@gmail.com, Tel.: 09954801220.
*
Abstract
Gd doped (0.02, 0.04 mol) TiO2 nanoparticles are prepared
by sol-gel method. X-ray diffraction reveals presence of anatase phase. XPS spectra ascertains trivalent state of the gadolinium ions. Room temperature M-H curve of the doped samples shows presence of both ferromagnetic (at low field) and
paramagnetic part (at high field).
Keywords: anatase, XRD, XPS, ferromagnetic, paramagnetic.
Figure
Introduction
Diluted magnetic semiconductor are key materials for
spin electronics [1]. TiO2 is an important semiconductor
with a wide band gap and an ideal host for accommodation of rare-earth emitters in view of its mechanical,
optical and thermal properties. Recently rare-earth
doped DMS have caught up great interests because of
their unique fluorescence properties and due to the high
emission quantum yields. In rare earth ions magnetism
arises from the 4f incomplete shell. The 4f electrons
undergo indirect exchange interactions via 5d or 6s conduction electrons resulting in high magnetic moment per
atoms due to high orbital momentum [2]. Room temperature ferromagnetism in Gd doped GaN was observed
by Liu.et.al [3]. The magnetic nature in their sample
was reported owing to the interaction of Gd 4f spins via
p-d coupling comprising holes introduced by the intrinsic defects. Adhikary.et.al [4] studied the magnetism in
Gd doped SnO2 nanoparticles prepared by a simple coprecipitation method. The magnetic nature of their samples revealed absence of ferromagnetic and anti ferromagnetic ordering in all the samples. Subramanian.et.al
[5] reported an in-depth study of magnetism in Gd
doped ZnO thin films prepared via spray pyrolysis
method. Hysteresis measurements indicated that the
samples are magnetically anisotropic and exhibit intrinsic ferromagnetic behavior at room temperature Theoretical analysis have also been carried out to explain the
observed ferromagnetism. In a report by Dalpian and
Wei [3] direct coupling between Gd atoms was found to
be antiferromagnetic in nature. The ferromagnetic phase
was stabilized by the electrons due to the mixing of Gd f
with host s states.
Fig.1: RT M-H curve of Gd doped TiO2 nanoparticles.
Acknowledgment
We are thankful to (SAIF), NEHU, Shillong for
providing the HRTEM images, IIT Kanpur for magnetic
measurement results and IICT Hyderabad for XPS
datas. We are also thankful to UGC for financial support
to the project F.No.42-785/2013 (SR).
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