NOPR Collection:
http://nopr.niscair.res.in/handle/123456789/2621
2016-12-09T05:40:48ZElectronic structure and electric field gradient calculations for H⁺ and μ⁺ in simple metals using spherical solid model
http://nopr.niscair.res.in/handle/123456789/2731
Title: Electronic structure and electric field gradient calculations for H⁺ and μ⁺ in simple metals using spherical solid model
Authors: Pal, B; Singh, J; Singh, Pawan; Chaturvedi, D K
Abstract: The electronic structure and electric field gradient (EFG) for H⁺ and μ⁺ in simple metals have been investigated. H⁺ and μ⁺ occupy octahedral site in fcc metals. The EFG arises due to the valence and size differences between impurity and host atoms. The former contribution has been evaluated using the impurity induced charge density calculated self-consistently using the spherical solid model potential for discrete lattice and Blatt’s correction for lattice dilation. The latter contribution has been evaluated in the elastic continuum model considering the dressed point ions interacting through screened Coulomb potential. The scattering phase shifts, impurity potential, induced charge density and EFG have been calculated. The phase shifts are found to be slowly converging and these are more prominent in Al than in Cu. Both the valence and size effect EFGs are found cylindrically symmetric yielding the asymmetry parameter (η) to be zero. The size effect EFG is found to be dominating at both the first and second nearest neighbours.
Page(s): 950-9582007-12-01T00:00:00ZDetermination of Allan deviation of Cesium atomic clock for lower averaging time
http://nopr.niscair.res.in/handle/123456789/2729
Title: Determination of Allan deviation of Cesium atomic clock for lower averaging time
Authors: Banerjee, P; Chatterjee, Arundhati
Abstract: Absolute Allan deviation of the Cesium clock for averaging time (τ) of 5 days or more may be calculated from the corresponding data of circular T published by Bureau International des Poids et Mesures (BIPM). For lower values of τ, the Allan deviation may indirectly be found from the extrapolation of these values through τ¹/² fit as recommended by CCTF-WGMRA guidelines. Absolute Allan deviation may also be directly found out by inter-comparison of minimum three clocks assuming that the noise in all clocks is fully uncorrelated. This paper analyses the values of Allan deviation determined by the direct method keeping in mind the limitation of the measurement system. These values of Allan deviation tally well with those found from the data of circular T.
Page(s): 945-9492007-12-01T00:00:00ZSpecific heat jump in anisotropic YBa₂Cu₃O₇₋δ superconductor
http://nopr.niscair.res.in/handle/123456789/2727
Title: Specific heat jump in anisotropic YBa₂Cu₃O₇₋δ superconductor
Authors: Khanna, K M; Kirui, M S Karap; Sakwa, T W; Torongey, P K; Ayodo, K Y; Rotich, S
Abstract: Using the exotic pairing model, the jump in the specific heat ΔC/Tc in YBa₂Cu₃O₇₋δ, for both breathing mode and buckling mode has been calculated. Its value was compared with the experimental values and it has been found that the specific heat jump in superconductor and the density of states were one fifth of the earlier reported values. This is indicative of the small fraction of carriers close to the Fermi level, which are paired and exotic pairing due to anharmonic perturbation of the apical oxygen ions leads to a lowering of ΔC/Tc.
Page(s): 991-9932007-12-01T00:00:00ZGrowth and characterization of In-Sb thin film structure
http://nopr.niscair.res.in/handle/123456789/2724
Title: Growth and characterization of In-Sb thin film structure
Authors: Mangal, R K; Tripathi, B; Singh, M; Vijay, Y K; Rais, A
Abstract: Thin films of InSb have been obtained by resistive heating method at the pressure 10⁻⁵ torr. Mixing of these bilayers has been done by rapid thermal annealing as well as vacuum annealing process. Characterizations of these films have carried out by optical band gap, Rutherford backscattering and X-ray diffraction studies. Obtained results indicate formation of InSb semiconductor.
Page(s): 987-9902007-12-01T00:00:00Z