Papers by Satyajit Banerjee
Journal of Physics: Conference Series
View the article online for updates and enhancements. Related content Observation of anomalous ad... more View the article online for updates and enhancements. Related content Observation of anomalous admixture of superconducting and magnetic fractions in BaFe2xCoxAs2 single crystals Biplab Bag, K Vinod, A Bharathi et al.-Anisotropic magnetic fluctuations in YbRh 2 Si 2 S Kambe, H Sakai, Y Tokunaga et al.
Imaging the spatial distribution of transport currents and the phenomenon of nanoscale phase sepa... more Imaging the spatial distribution of transport currents and the phenomenon of nanoscale phase separation phenomenon in CMR materials.
We show that by nano-patterning a superconductor (NbSe 2 single crystal) with an array of blind h... more We show that by nano-patterning a superconductor (NbSe 2 single crystal) with an array of blind holes produces significant magnetic field sweep rate dependent metastable magnetization response. Our results are explained on the basis of a unique collective action of the blind holes pins which creates a barrier against vortex redistribution inside the sample. We propose that this barrier leads to a phase separation creating distinct population of vortices viz., those pinned on blind holes and those confined in the interstitials between the holes.
We show that by nano-patterning a superconductor (NbSe $ _ {2} $ single $ _ {} $ crystal) with an... more We show that by nano-patterning a superconductor (NbSe $ _ {2} $ single $ _ {} $ crystal) with an array of blind holes produces significant magnetic field sweep rate dependent metastable magnetization response [1]. Our results are explained on the basis of a unique collective action of the blind holes pins which creates a barrier against vortex redistribution inside the sample. We propose that this barrier leads to a phase separation creating distinct population of vortices viz., those pinned on blind holes and those confined in the ...
We investigate the magnetic properties of a composite comprising of ferromagnetic Cobalt nanowire... more We investigate the magnetic properties of a composite comprising of ferromagnetic Cobalt nanowires embedded in nanoporous anodized alumina template. We observe unusual increase in, the saturation magnetization and the coercive field, of the nanowires below 100 K. We also report the appearance of an unusual exchange bias effect in nanowires below 100 K. We argue our results can be understood on the basis of a competition between different magnetic energy scales induced by significant stresses acting on the nanowires at low temperatures. The composite behaves as an effective medium in which the magnetic anisotropy of nanowires can be conveniently controlled via stress on the nanowires.
New Journal of Physics, 2012
Using high sensitivity magneto-optical imaging we find evidence for a jump in local vortex densit... more Using high sensitivity magneto-optical imaging we find evidence for a jump in local vortex density associated with a vortex liquid to solid phase transition just above the lower critical field in a single crystal of Bi 2 Sr 2 CaCu 2 O 8. We find the regions of the sample where the jump in vortex density occurs are associated with low screening currents. In the field-temperature vortex phase diagram we identify phase boundaries demarcating a dilute vortex liquid phase and the vortex solid phase. The phase diagram also identifies a coexistence regime of the dilute vortex liquid and solid phases and shows the effect of pinning on the vortex liquid to solid phase transition line. We find the phase boundary lines can be fitted to the theoretically predicted expression for the low-field portion of the phase boundary delineating a dilute vortex solid from a vortex liquid phase. We show that the same theoretical fit can be used to describe the pinning dependence of the low-field phase boundary lines provided a dependence of the Lindemann number on pinning strength is considered.
Physica C: Superconductivity, 2000
The characteristic details of the path dependence in the in-phase ac susceptibility data are eluc... more The characteristic details of the path dependence in the in-phase ac susceptibility data are elucidated via provision of an external stimulus and the process of thennal cyclings across the multiple steps comprising fl~e peak effect (PE) phenomenon in a single crystal of Yb3Rh4Snl3.
Using a combination of magnetic decoration and dierential magneto-optical techniques we have stud... more Using a combination of magnetic decoration and dierential magneto-optical techniques we have studied the interrelation between the order of the vortex liquid-solid phase transition and the corresponding structure of the vortex solid phase in Bi2Sr2CaCu2O8 crystals with dierent doses of columnar defects (CDs). The magnetic decoration makes evident that when the number of vortices exceeds that of CDs, the vortex solid state is a heterogeneous system containing two species of vortices: A network of grain boundaries associated with vortices pinned on CDs surrounding regions free of columnar defects where Abrikosov microcrystals solidify. On the other hand, when the number of vortices is smaller than that of columnar defects the structure of the vortex solid is amorphous. The vortex liquid-solid phase transition as determined by dierential magneto- optical experiments shows that the first-order melting phase transition does not require a structural symmetry break as usually found in natu...
Physica B: Condensed Matter, 1997
We report the magnetic phase diagram of a clean single crystal of 2H-NbSe2 and present an update ... more We report the magnetic phase diagram of a clean single crystal of 2H-NbSe2 and present an update on the determination of its intrinsic superconducting parameters.
Imaging the characteristics of the sample, and a system and method for identifying the area of ... more Imaging the characteristics of the sample, and a system and method for identifying the area of the damage in the sample is generally described as. Some exemplary systems and methods for non-destructive evaluation of the area of the material is, DC to the system imaging directly the area of the material is weak structural damage resulting from the imaging magnetic field produced by the DC current coupled with a material ( It may operate in a direct current) mode. Some exemplary systems, to produce a time variant magnetic field due to the AC excitation coil to induce eddy current in the sample, and imaging the area of the material are damage resulting from the image the magnetic field generated by the eddy current around the area of damage for it may operate in AC (alternating current) mode. System may, for example, by using the magneto-optical imaging techniques (MOI) to measure the channel and the magnetic field of the current flow in the material, and map.
We investigate the magnetic properties of a composite comprising of ferromagnetic Cobalt nanowire... more We investigate the magnetic properties of a composite comprising of ferromagnetic Cobalt nanowires embedded in nanoporous anodized alumina template. We observe unusual increase in, the saturation magnetization and the coercive field, of the nanowires below 100 K. We also report the appearance of an unusual exchange bias effect in nanowires below 100 K. We argue our results can be understood on the basis of a competition between different magnetic energy scales induced by significant stresses acting on the nanowires at low temperatures. The composite behaves as an effective medium in which the magnetic anisotropy of nanowires can be conveniently controlled via stress on the nanowires.
The effect of disorder on flux line lattice (FLL) melting is studied via the Peak Effect phenomen... more The effect of disorder on flux line lattice (FLL) melting is studied via the Peak Effect phenomenon. On the upper branch of the Peak Effect curve, where this effect is more robust, we observe a stepwise disordering of the FLL, suggesting two first order transition spanning the Peak Effect region. The lower part of the curve is found to be
Superconductivity - Theory and Applications, 2011
Superconductor Science and Technology, 2012
Magneto-optical imaging studies in a single crystal of Bi 2 Sr 2 CaCu 2 O 8 partially patterned w... more Magneto-optical imaging studies in a single crystal of Bi 2 Sr 2 CaCu 2 O 8 partially patterned with a hexagonal array of pinning centers (blind holes) reveals local features in the patterned region which are distinct compared to the pristine unpatterned regions in the sample. The patterned area exhibits a strongly diamagnetic local magnetization response and is characterized by a local penetration field enhanced by a factor of three. We show that strong shielding currents around the periphery of the nanopatterned region create a barrier which prevents vortex entry into the patterned region thus sustaining an effectively flux-free state upto the enhanced penetration field.
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Papers by Satyajit Banerjee