The evolution of ferromagnetism has been investigated in thiol (2-mercaptoethanol) capped Mn doped CdS nanoparticles synthesized at various temperatures by sol-gel reverse micelle mechanism. X-ray diffraction measurements reveal a structural phase transformation from wurtzite to zinc blende structure with the increase in synthesis temperature of Mn doped nanocryatals. Magnetic measurements suggest that the antiferromagnetic interactions of Mn2+ ions within Mn—cluster in Mn doped CdS nanocrystals synthesized at lower temperature (∼17 °C) reduce the total magnetic moment at ambient temperature. Whereas the isolated Mn2+ ions in nanocrystals synthesized above 70 °C enhance the magnetic moment due to the sp-d exchange interaction at ambient temperature. It has been observed that the magnetic moments in all samples synthesized at various temperatures do not saturate even at lowest temperature, 5 K. The core diamagnetism in doped nanocrystals synthesized at low temperature (∼17 °C) is mostly due to the presence of magnetic ions around the surface, whereas these ions exist randomly throughout the crystal for samples synthesized at high temperature (∼70 °C), as a result core diamagnetism vanishes.

1.
A. P.
Alivisatos
,
J. Phys. Chem.
100
,
13226
(
1996
).
3.
C. B.
Murray
,
D. J.
Norris
, and
M. G.
Bawendi
,
J. Am. Chem. Soc.
115
,
8706
(
1993
).
4.
Z. A.
Peng
and
X.
Png
,
J. Am. Chem. Soc.
123
,
183
(
2001
).
5.
S. A.
Wolf
,
D. D.
Awschalom
,
R. A.
Buhrman
,
J. M.
Daughton
,
S.
von Molnár
,
M. L.
Roukes
,
A. Y.
Chtchelkanova
, and
D. M.
Treger
,
Science
294
,
1488
(
2001
).
6.
S.
Nazir
,
N.
Ikram
,
M.
Tanveer
,
A.
Shaukat
,
Y.
Saeed
, and
A. H.
Reshak
,
J. Phys. Chem. A
113
,
6022
(
2009
).
7.
T.
Dietl
,
H.
Ohono
,
F.
Matsukar
,
J.
Cibert
, and
D.
Ferrand
,
Science
287
,
1019
(
2000
).
8.
C.
Madhu
,
A.
Sundaresan
, and
C. N. R.
Rao
,
Phys. Rev. B
77
,
201306
(
2008
).
9.
G. P.
Das
,
B. K.
Rao
, and
P.
Jena
,
Phys. Rev. B
68
,
35207
(
2003
).
10.
Q.
Wang
,
Q.
Sun
, and
P.
Jena
,
Phys. Rev. Lett.
95
,
167202
(
2005
).
11.
H. K.
Seong
,
J. Y.
Kim
,
J. J.
Kim
,
S. C.
Lee
,
S. R.
Kim
,
U.
Kim
,
T. E.
Park
, and
H. J.
Choi
,
Nano Lett.
7
,
3366
(
2007
).
12.
S.
Delikanli
,
S.
He
,
Y.
Qin
,
P.
Zhang
, and
H.
Zeng
,
Appl. Phys. Lett.
93
,
132501
(
2008
).
13.
S.
Bhattacharyya
,
Y.
Estrin
,
D. H.
Rich
,
D.
Zitoun
,
Y.
Koltypin
, and
A.
Gedanken
,
J. Phys. Chem. C
114
,
22002
(
2010
).
14.
S.
Taguchi
,
A.
Ishizumi
,
T.
Tayagaki
, and
Y.
Kanemitsu
,
Appl. Phys. Lett.
94
,
173101
(
2009
).
15.
H.
Saito
,
W.
Zaets
,
S.
Yamagata
,
Y.
Suzuki
, and
K.
Ando
,
J. Appl. Phys.
91
,
8085
(
2002
).
16.
A.
Sundaresan
and
C. N. R.
Rao
,
Nano Today
4
,
96
(
2009
).
17.
S.
Banerjee
,
M.
Mandal
,
N.
Gayathri
, and
M.
Sardar
,
Appl. Phys. Lett.
91
,
182501
(
2007
).
18.
G. M.
Dalpian
and
J. R.
Chelikowsky
,
Phys. Rev. Lett.
96
,
226802
(
2006
).
19.
A.
Nag
,
S.
Chakraborty
, and
D. D.
Sarma
,
J. Am. Chem. Soc.
130
,
10605
(
2008
).
20.
N. S.
Karan
,
S.
Sarkar
,
D. D.
Sarma
,
P.
Kundu
,
V.
Ravishankar
, and
N.
Pradhan
,
J. Am. Chem. Soc.
133
,
1666
(
2011
).
21.
L.
Levy
,
J. F.
Hochepied
, and
M. P.
Pileni
,
J. Phys. Chem.
100
,
18322
(
1996
).
22.
T.
Torimoto
,
J. P.
Reyes
,
K.
Iwasaki
,
B.
Pal
,
T.
Shibayama
,
K.
Sugawara
,
H.
Takahashi
, and
B.
Ohtani
,
J. Am. Chem. Soc.
125
,
316
(
2003
).
23.
See supplementary material at http://dx.doi.org/10.1063/1.4820258 for determination of crystal phase and XRD spectra of thiol capped Mn-doped CdS nanoparticles prepared at different cyclic temperatures, UV-visible and Fluorescence spectra of samples, theoretical estimation of particle size from UV-visible spectra, and estimation of Mn from M-H curves. These analysis and figures are not necessary for an overall understanding of the scientific arguments presented here but may be of interest to some readers.
24.
D. J.
Norris
,
N.
Yao
,
T. T.
Charnok
, and
T.
Kennedy
,
Nano Lett.
1
,
3
(
2001
).
25.
R. N.
Bhargava
,
D.
Gallagher
,
X.
Hong
, and
A.
Nurmikko
,
Phys. Rev. Lett.
72
,
416
(
1994
).
26.
A. D.
Lad
,
C.
Rajesh
,
M.
Khan
,
N.
Ali
,
T. K.
Gopalakrishnan
,
S. K.
Kulshreshtha
, and
S.
Mahamuni
,
J. Appl. Phys.
101
,
103906
(
2007
).
27.
J. M. D.
Coey
,
M.
Venkatesan
, and
C. B.
Fitzgerald
,
Nature Mater.
4
,
173
(
2005
).
28.
G.
Lawes
,
A. S.
Risbud
,
A. P.
Ramirez
, and
R.
Seshadri
,
Phys. Rev. B
71
,
045201
(
2005
).
29.
M. S.
Seehra
,
P.
Dutta
,
S.
Neeleshwar
,
Y.-Y.
Chen
,
C. L.
Chen
,
S. W.
Chou
,
C. C.
Chen
,
C.-L.
Dong
, and
C.-L.
Chang
,
Adv. Mater.
20
,
1656
(
2008
).
30.
P.
Crespo
,
R.
Litran
,
T. C.
Rojas
,
M.
Multigner
,
J. M.
de la Fuente
,
J. C.
Sanchez-Lopez
,
M. A.
Garcia
,
A.
Hernando
,
S.
Penades
, and
A.
Fernandez
,
Phys. Rev. Lett.
93
,
087204
(
2004
).
31.
A.
Quesada
,
M. A.
Garcia
,
J.
de la Venta
,
E.
Fernandez Pinel
,
J. M.
Merino
, and
A.
Hernando
,
Eur. Phys. J. B
59
,
457
(
2007
).
32.
H.
Mattoussi
,
A. W.
Cumming
,
C. B.
Murray
,
M. G.
Bawendi
, and
R.
Ober
,
J. Chem. Phys.
105
,
9890
(
1996
).
33.
A.
Ghosh
,
S.
Paul
, and
S.
Raj
,
Solid State Commun.
154
,
25
(
2013
).
34.
B.
Sambandam
,
N.
Rajendran
,
M.
Kanagaraj
,
S.
Arumugam
, and
P. T.
Manoharan
,
J. Phys. Chem. C
115
,
11413
(
2011
).
35.
D.
Karmakar
,
S. K.
Mandal
,
R. M.
Kadam
,
P. L.
Paulose
,
A. K.
Rajarajan
,
T. K.
Nath
,
A. K.
Das
,
I.
Dasgupta
, and
G. P.
Das
,
Phys. Rev. B
75
,
144404
(
2007
).
36.
D. L.
Leslie-Pelecky
and
R. D.
Rieke
,
Chem. Mater.
8
,
1770
(
1996
).
37.
P. A.
Joy
,
P. S. A.
Kumar
, and
S. K.
Date
,
J. Phys.: Condens. Matter
10
,
11049
(
1998
).
38.
X. G.
Li
,
X. J.
Fan
,
G.
Ji
,
W. B.
Wu
,
K. H.
Wong
,
C. L.
Choy
, and
H. C.
Ku
,
J. Appl. Phys.
85
,
1663
(
1999
).
39.
A.
Chakraborty
,
P.
Wenk
,
R.
Bouzerar
, and
G.
Bouzerar
,
Phys. Rev. B
86
,
214402
(
2012
).

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