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Chatterjee S.,Indian Association for The Cultivation of Science | Singh V.R.,Indian Association for The Cultivation of Science | Deb A.K.,Raiganj College University College | Giri S.,Indian Association for The Cultivation of Science | And 4 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2010

The magnetic properties of the cubic Heusler alloys with nominal compositions Ni2 + x Mn1 - xIn have been investigated experimentally as well as theoretically using first principles electronic structure calculations. Magnetization measurements indicate that all the alloys considered in this work have ferromagnetic ground state. The Curie temperature and the saturation moment of the samples are found to decrease systematically with increasing Ni concentration. No indication of structural transition was evident from our experimental data recorded down to 5 K. Electronic structure calculation indicates that localized magnetic moments are predominantly contributed by the Mn atoms and the calculated magnetic moment as a function of excess Ni concentration agrees well with the experimental data. © 2009 Elsevier B.V. All rights reserved.

Acharya S.,University of Burdwan | Sutradhar S.,University of Burdwan | Mandal J.,University of Burdwan | Mukhopadhyay K.,University of Burdwan | And 2 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2012

Nanocrystalline BiFeO 3 and rare earth ion doped BiFeO 3 (Bi 0.9R 0.1FeO 3, R=Er and Tm) were prepared by sol-gel method. Rietveld analysis of the X-ray diffractograms of the samples revealed that small amount of impurity phase of Bi 2Fe 4O 9 was formed together with the desired phase. In the thermal variation of magnetic mass susceptibility (χ m) of the samples, one sharp transition below T M (T M∼100 K, 50 K and 30 K for BiFeO 3, Bi 0.9Er 0.1FeO 3 and Bi 0.9Tm 0.1FeO 3, respectively) was observed, which clearly hint the change of the domination of the ferromagnetic exchange interaction over the usual antiferromagnetic exchange interaction. Also, static magnetization (M) and susceptibility of each doped sample have been drastically enhanced compared to that of BiFeO 3. The values of χ m and M measured at different temperatures confirmed that the magnetic behavior of the doped systems has been dominated by the paramagnetic/ferromagnetic clusters below ∼T M. Another phase transition were observed in the χ m vs. T curve of the samples at relatively higher temperature T B (∼260 K for BiFeO 3, ∼220 K for Bi 0.9Er 0.1FeO 3 and ∼180 K for Bi 0.9Tm 0.1FeO 3), which may be attributed to the charge ordering transition. Ferroelectric hysteresis loops of the samples observed at 100 Hz confirmed the presence of ferroelectric ordering of the samples. Measured values of dielectric constants at 1 kHz of each sample in presence and absence of magnetic field confirmed a substantial magnetoelectric coupling of all the samples. © 2012 Elsevier B.V. All rights reserved.

Chatterjee A.,Raiganj College University College
International Journal of ChemTech Research | Year: 2013

Ethanol electro-oxidations on to platinum surface have been reported in surfactant environment. Analysis of the cyclicvoltammtry results shows that ethanol (EtOH) solution containing surfactants show a remarkable depression of all the peak current as compared to only ethanol solution. It is observed that in the presence of SDS (sodium dodecyl sulfate) the oxidation current of EtOH is reduced to a small extent but it is reduced to a large extent in the presence of CTAB (cetyl trimethyl ammonium bromide). Again, it is revealed from the study that both oxidation potential and the peak current are function of surfactant concentration.

Malik K.,University of Calcutta | Das D.,University of Calcutta | Bandyopadhyay S.,University of Calcutta | Mandal P.,Saha Institute of Nuclear Physics | And 3 more authors.
Applied Physics Letters | Year: 2013

Thermal variation of structural property, linear thermal expansion coefficient (α), resistivity (ρ), thermopower (S), and power factor (PF) of polycrystalline Bi1-xSbx (x = 0.10 and 0.14) samples are reported. Temperature-dependent powder diffraction experiments indicate that samples do not undergo any structural phase transition. Rietveld refinement technique has been used to perform detailed structural analysis. Temperature dependence of α is found to be stronger for Bi 0.90Sb0.10. Also, PF for direct band gap Bi 0.90Sb0.10 is higher as compared to that for indirect band gap Bi0.86Sb0.14. Role of electron-electron and electron-phonon scattering on ρ, S, and PF has been discussed. © 2013 AIP Publishing LLC.

Saha M.R.,North Bengal University | De Sarker D.,Raiganj College University College | Sen A.,North Bengal University
Indian Journal of Traditional Knowledge | Year: 2014

Present study aimed at documenting and analyzing the ethnoveterinary practices of domesticated animals and birds of Malda district of West Bengal in India. Successive field surveys were conducted to assemble data from tribal practitioners by means of semi-structured individual interviews, open ended questionnaires, informal interviews, group discussion, etc. Present study recorded 70 phytotherapeutic practices involving 60 plants which were used to treat 34 types of disease and disorders of livestock. Out of 34 livestock disease and disorders, mostly treated ailment was agalactia with 7 different therapeutic uses followed by fever, treated with 5 different preparations. Leaves were most frequently used plant parts in preparing medicinal formulations. However, five new ethnoveterinary formulations were documented during this survey for the first time. The informants' consensus factor (FIC) was found very high (0.88 - 1) establishing the study more authentic. This is the first detailed documentation of ethnoveterinary knowledge as well as first report of determining FIC among the tribal communities of this region.

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