Debasis Sen

Publications (50) View all

• Article: Single scattering profile from small-angle scattering data affected by multiple scattering: use of a basis function set

  D. Sen, J. Bahadur, S. Mazumder
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  ABSTRACT: Present work involves extraction of single-scattering profile from small-angle scattering data, affected by multiple scattering, using an existing model-independent algorithm [Mazumder etal., Physica B 241–243, 1222 (1998), Mazumder et al., J. Appl. Crystallogr. 36, 840 (2003)]. It is shown that implementation of the algorithm becomes effective by representing the multiple scattering profiles in terms of a set of basis function whose form of Hankel transformed pair is known analytically. In the present paper, the methodology has been presented by introducing a Gaussian basis set and has been tested for various simulated profiles. The performance of this methodology has also been tested for scattering profiles having complex internal features and moderate statistical noise. Subsequently, the same has been applied for experimental small-angle neutron scattering data.
  Physics of Condensed Matter 04/2012; 71(1):75-84. · 1.53 Impact Factor
• Source

  Available from: Jitendra Bahadur

  Article: Effects of sintering on microstructure and dielectric response in YCrO3 nanoceramic

  J. Bahadur, D. Sen, S. Mazumder, V. K. Aswal, V. Bedekar, R. Shukla, A. K. Tyagi
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  ABSTRACT: Effects of sintering on pore morphology and dielectric response have been investigated. Pore structure has been probed by small angle neutron scattering (SANS). It has been observed that the size distribution becomes less polydisperse with a slight modification in the distribution as sintering temperature is increased. Dielectric response in the frequency range 0.02–1000 kHz is significantly altered by modification of pore structure because of sintering. A transition from non-Debye type to near-Debye type response has been observed as the sintering temperature is increased.
  Pramana 04/2012; 71(5):959-963. · 0.57 Impact Factor
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  Available from: Jitendra Bahadur

  Article: Investigation on pore structure and small-scale agglomeration behaviour in liquid phase sintered SiC using small angle neutron scattering

  D. Sen, J. Bahadur, S. Mazumder, T. Mahata, M. Syambabu, P. K. Sinha
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  ABSTRACT: Mesoscopic density fluctuations in liquid phase sintered silicon carbide have been investigated using small angle neutron scattering (SANS). The increase in the additives results in the modification in the pore size distribution and to some extent the total porosity. SANS revealed a mass fractal nature of the agglomerated matrix microstructure. The fractal dimension of the matrix does not change appreciably with the additives although the upper cut-off value of the fractal decreases significantly with the increase in the additives. The liquid phase sintering due to the presence of additives helps to achieve higher level of densification. However, the agglomeration hinders achievement of the fully dense pellets.
  Pramana 04/2012; 71(5):979-984. · 0.57 Impact Factor
• Source

  Available from: ias.ac.in

  Article: Characterization of porous materials by small-angle scattering

  S. Mazumder, D. Sen, A. K. Patra
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  ABSTRACT: Characterization of porous materials by small-angle scattering has been extensively pursued for several years now as the pores are often of mesoscopic size and compatible with the length scale accessible by the technique using both neutrons and X-rays as probing radiation. With the availability of ultra small-angle scattering instruments, one can investigate porous materials in the sub-micron length scale. Because of the increased accessible length scale vis-a-vis the multiple scattering effect, conventional data analysis procedures based on single scattering approximation quite often fail. The limitation of conventional data analysis procedures is also pronounced in the case of thick samples and long wavelength of the probing radiation. Effect of multiple scattering is manifested by broadening the scattering profile. Sample thickness for some technologically important materials is often significantly high, as the experimental samples have to replicate all its essential properties in the bulk material. Larger wavelength of the probing radiation is used in some cases to access large length scale and also to minimize the effect of double Bragg reflections.
  Pramana 04/2012; 63(1):165-173. · 0.57 Impact Factor
• Article: Nanocomposite Silica Surfactant Microcapsules by Evaporation Induced Self Assembly: Tuning the morphological buckling by modifying viscosity and surface charge

  D. Sen, J. Bahadur, S. Mazumder, G. Verma, P. A. Hassan, S. Bhattacharya, K. Vijai, P. Doshi
  Soft Matter 01/2012; 8:1955-1963. · 4.39 Impact Factor