Vikas Nandwana

Dr. Vikas Nandwana

Northwestern University
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 November 2006 in Advanced Materials
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Journal Article
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CRC.‐B. Rong
C.‐B. Rong
DLD. Li
D. Li
VNVikas Nandwana
Vikas Nandwana
NPN. Poudyal
N. Poudyal
YDY. Ding
Y. Ding
JLJ. P. Liu
J. P. Liu

1 July 2005 in Journal of Physics D: Applied Physics
Verified
Journal Article
Closed access
KEKevin Elkins
Kevin Elkins
DLDaren Li
Daren Li
NPNarayan Poudyal
Narayan Poudyal
VNVikas Nandwana
Vikas Nandwana
ZJZhiqiang Jin
Zhiqiang Jin
JLJ Ping Liu
J Ping Liu

24 February 2007 in The Journal of Physical Chemistry C
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Journal Article
Closed access
VNVikas Nandwana
Vikas Nandwana
KEKevin E. Elkins
Kevin E. Elkins
NPNarayan Poudyal
Narayan Poudyal
GCGirija S. Chaubey
Girija S. Chaubey
KYKazuaki Yano
Kazuaki Yano
JLJ. Ping Liu
J. Ping Liu

12 February 2013 in Journal of the American Chemical Society
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Journal Article
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DPDavid E. Przybyla
David E. Przybyla
CPCharles M. Rubert Pérez
Charles M. Rubert Pérez
JGJeremy Gleaton
Jeremy Gleaton
VNVikas Nandwana
Vikas Nandwana
JCJean Chmielewski
Jean Chmielewski

15 April 2006 in Journal of Applied Physics
Verified
Journal Article
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DLDaren Li
Daren Li
NPNarayan Poudyal
Narayan Poudyal
VNVikas Nandwana
Vikas Nandwana
ZJZhiqiang Jin
Zhiqiang Jin
KEKevin Elkins
Kevin Elkins
JLJ. Ping Liu
J. Ping Liu
To transfer face-centered-cubic (fcc) FePt nanoparticles to the face-centered-tetragonal (fct) phase with high magnetic anisotropy, heat treatments are necessary. The heat treatments lead to agglomeration and sintering of the nanoparticles. To prevent the particles from sintering, salts as the separating media (matrix) have been used for annealing the nanoparticles in our experiments. The fcc nanoparticles produced by chemical synthesis were mixed with NaCl powders. The mixture was then annealed in forming gas (93%H2+7%Ar) in different conditions to complete the fcc to fct phase transition. After the annealing, the salt was washed out by water and monodisperse fct FePt nanoparticles were obtained. Detailed studies on the effect of the NaCl-to-FePt weight ratios (from 1:1 to 400:1) have been performed. It was found that a suitable NaCl-to-FePt ratio is the key to obtain monodisperse fct FePt nanoparticles. A higher NaCl-to-FePt ratio is needed for larger particles when the annealing conditions are the same. Increased annealing temperature and time should be accompanied by a higher NaCl-to-FePt ratio. Magnetic measurements show very high coercivity (up to 30 kOe) of the monodispersed fct nanoparticles by the salt-matrix annealing.

1 January 2009 in Journal of Applied Physics
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Journal Article
Closed access
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VNVikas Nandwana
Vikas Nandwana
GCGirija S. Chaubey
Girija S. Chaubey
KYKazuaki Yano
Kazuaki Yano
CRChuan-Bing Rong
Chuan-Bing Rong
JLJ. Ping Liu
J. Ping Liu
Bimagnetic FePt/Fe3O4 nanoparticles with core/shell or heterodimer structure have been prepared using a sequential synthetic method. The dimension of both FePt and Fe3O4 was tuned by varying the synthesis parameters. The as-synthesized bimagnetic nanoparticles were superparamagnetic at room temperature. After being annealed in a reducing atmosphere, the FePt/Fe3O4 bimagnetic nanoparticles were converted to a hard magnetic nanocomposite with enhanced energy products due to the exchange coupling between the hard and soft magnetic phases. It was found that the exchange coupling in nanocomposites made from the core/shell nanoparticles is stronger than that from the heterodimer nanoparticles. By tuning the dimensions of the FePt and Fe3O4 phases, the energy product up to 17.8 MGOe was achieved in the annealed nanocomposites, which is 36% higher than the isotropic single-phase FePt counterpart.