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Education: M.Sc.,-University of Madras (1977)- First class: Ph.D -
Indian Institute of technology (IIT)- Madras (1983)
Awards and fellowship:
French government t scholar at CRTBT-CNRS Grenoble (1983-84) RA at University Hamburg (1985-86) Invited as Honorary visiting faculty S.N.Bose Institute- Calcutta (2005) Material Research Society of India- Medal (2007) SINP foundation day award (2010): Highest citation category from SINP
Research programme 2007-09:
We summarize some of the recently reported new experimental results as: (i) The interest in spinel oxides stems from the fact that spinel ferrite (nano) particle is an ideal small particle magnetic system whose crystal chemistry can be controlled where as for pure metal particles the crystal chemistry is basically fixed. We have reported the increase of magnetization below AFM ordering, unconventional relaxation in AFM nano particle and enhancement of surface magnetization in CoRh2O4, lattice expansion and magnetism in MnCr2O4. A Core-shell model has been proposed by us to explain the AFM nano particles (ii) Further we have also shown the possibility of negative temperature coefficient of resistivity (NTCR) in the absence of chemical / structural disorder, negative thermal expansion (NTE) in AFM pervoskite materials GdPd3BxC1-x. This work also establishes some synergy between isotropic NTE and NTCR in these magnetic intermetallic compounds. We have also observed negative giant magnetoresistance (GMR) in cubic TbPd3(-30%), which is the highest among the RPd3 series. This programme is in collaboration with Dr R.N.Bhowmik ,Mr Abhishek Pandey ,Prof C.Mazumdar for intermetallic alloys .
Recent important publications :
a) Intermetallic anti pervoskite materials:
Abhishek Pandey etal Applied Physics Letter 94 182503 (2009) : Applied Physics Letter 94 172509 (2009): J.Phys. Cond. Matter 21 216002 (2009): J. Magn. Magn. Materials 321 2311 (2009) :J.alloys and compounds 476 14 (2009): Euro. Phy. Lett. 84 47007 (2008) : Applied Physics Letter 92 261913 (2008) . J.Magn.Mag.Material
b) Small particle magnetism
R.N.Bhowmik etal J.applied Physics 95 113909 (2009): Phy. Rev. B 75 012410 (2007) :Phy.Rev B 74 214417 (2006) :Phy.Rev B 73 144413 (2006) :Phy.Rev B 2005 72 094405 (2005):Phys. Rev B 69 054430 (2004): Phys. Rev B 68 134433 (2003) .Anulekha Dutta etal Physical Rev B 68 054432 (2003)
c) Composite magnets
N.V.Ramarao etal J. Phys. D: Appl. Phys 41 065001 (2008) : J. Magn. Magn. Mater. 312 252 (2007):
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