Swift heavy ion induced structural and
luminescence characterization of Y
2
O
3
:Eu
3+
phosphor: a comparative study
S. Som,
a
S. K. Sharma
a
* and S. P. Lochab
b
ABSTRACT: We report a comparative study on structural and thermoluminescence modifications of Y
2
O
3
:Eu
3+
phosphor
induced by 150 MeV Ni
7+
, 120 MeV Ag
9+
and 110 MeV Au
8+
swift heavy ions (SHI) in the fluence range 1Â 10
11
to 1Â 10
13
ions/cm
2
. X-Ray diffraction and transition electron microscopy studies confirm the loss of crystallinity of the phosphors after
ion irradiation, which is greater in the case of Au ion irradiation. Structural refinement using the Rietveld method yields the
various structural parameters of ion-irradiated phosphors. Thermoluminescence glow curves of ion-irradiated phosphors
show a small shift in the position of the peaks, along with an increase in intensity with ion fluence. Stopping range of ions
in Matter (SRIM) calculations were performed to correlate the change in thermoluminescence properties of various ion-
irradiated phosphors. It shows that the defects created by 110 MeV Au
8+
ions are greater in number. Trapping parameters
of ion-irradiated phosphors were calculated from thermoluminescence data using various glow curve analysis methods.
Copyright © 2013 John Wiley & Sons, Ltd.
Keywords: phosphor; swift heavy ion; Rietveld refinement; trapping parameter
Introduction
Swift heavy ion (SHI)-induced modification of rare-earth-doped
phosphors has been extensively studied during the past few
decades for its practical applications in the fields of biology,
nuclear science and material science (1). When SHI passes
through a material intense electronic excitations occur along
the ion trajectory due to the inhomogeneous distribution of
energy inside the material (2). This internal disorder creates a
large number of defects inside the material. The characterization
of such defects provides materials with technological impor-
tance for different practical applications. Structural refinement
and thermoluminescence (TL) are well-established and very
sensitive techniques for the characterization of structural disor-
der and defects in solids (3).
Rare-earth-doped oxide phosphors play an important role in
modern display technology and radiation dosimetry due to their
high luminescence efficiency and good thermal and chemical
stability (3). Europium-doped yttrium oxide phosphors have been
studied by many researchers for red emission in display technol-
ogy (4). However, the use of SHI-induced Y
2
O
3
:Eu
3+
as a TL material
has not been reported to date. Keeping this in mind, structural re-
finement and TL studies of various ion-irradiated Eu
3+
-doped Y
2
O
3
were carried out. Trap levels in SHI-irradiated Eu
3+
-doped Y
2
O
3
were characterized for the first time using various TL glow curve
analysis techniques.
In this study, we compared the effects of various SHI on the
structure and trapping parameters of Y
2
O
3
:Eu
3+
phosphors. Struc-
tural refinement was performed with the Rietveld method (5) using
the FullProf program (6). Different structural parameters were
calculated using analytical methods (7). A Stopping range of ions
in Matter (SRIM) calculation (8) was performed to correlate the TL
properties of Y
2
O
3
:Eu
3+
with defect formation under SHI irradiation.
The TLanal computer program (9) was used to deconvolute the
composite TL glow curves. The trapping parameters of
deconvoluted peaks obtained with this program were compared
with the glow curve shape methods.
Experimental
Sample preparation
Eu-doped Y
2
O
3
phosphor was prepared by combustion synthesis
using europium oxide (Eu
2
O
3
), yttrium oxide (Y
2
O
3
), nitric acid
(HNO
3
) and urea [CO(NH
2
)
2
] as the starting raw materials. Stock so-
lutions of Y(NO
3
)
3
and Eu(NO
3
)
3
were prepared by dissolving Y
2
O
3
and Eu
2
O
3
in nitric acid and diluting with deionized water. Y(NO
3
)
3
and Eu(NO
3
)
3
were mixed in a beaker according to the formula
(Y
1–x
Eu
x
)
2
O
3
(x = 0.05). A suitable amount of urea was added to the
nitrate solution mixture, keeping the urea to metal nitrate molar
ratio as 2.5 (4). The mixture was then dissolved to achieve a uniform
solution and dried by heating at 80 °C using a magnetic stirrer.
Finally, the solid residue was transferred to a silica crucible and
heated at 600 °C in a furnace for 1 h. The synthesis reaction (4) was:
2–2x ð ÞY NO
3
ð Þ
3
þ 2xEu NO
3
ð Þ
3
þ 5 NH
2
ð Þ
2
CO→ Y
1Àx
Eu
x
ð Þ
2
O
3
þ 5CO
2
þ 8N
2
þ 10H
2
O:
* Correspondence to: S K Sharma, Department of Applied Physics, Indian
School of Mines, Dhanbad 826 004, India. Tel.: +913 262 235 412; Fax:
+91 326 229 6563. E-mail: sksharma.ism@gmail.com
a
Department of Applied Physics, Indian School of Mines, Dhanbad 826 004, India
b
Inter University Accelerator Centre, New Delhi 110 067, India
Luminescence 2014; 29: 480–491 Copyright © 2013 John Wiley & Sons, Ltd.
Research article
Received: 15 March 2013, Accepted: 02 August 2013 Published online in Wiley Online Library: 23 September 2013
(wileyonlinelibrary.com) DOI 10.1002/bio.2573
480