http://nopr.niscair.res.in/handle/123456789/8227 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/8400 Title: Temperature, current and doping dependence of non-ideality factor for <i style="">pnp </i>and <i style="">npn</i> punch-through structures <br/> <br/>Authors: Shah, Khurshed Ahmad; Islam, S S <br/> <br/>Abstract: The effect of punch-through in devices is of great importance in electronic industry. In this paper, an efficient, unconditionally stable, simple and accurate method has been presented for solving non-linear transport equations for carriers with appropriate choice of initial values of dependent variables. The methods are so fast that parameter dependence of non-ideality for punch-through structures has been incorporated easily and their specific effects have been determined precisely. The present study reveals that the non-ideality factor decreases with temperature and increases with current and doping concentration of the active region of the device. The relative changes are larger at lower temperatures and more effective at higher impurity density of the active region of the device. This study enables to have better understanding of the punch-through mechanism and design of these devices. <br/> <br/>Page(s): 953-958 http://nopr.niscair.res.in/handle/123456789/8399 Title: Cation distribution in mixed Mg-Mn ferrite systems from X-ray diffraction technique and saturation magnetization <br/> <br/>Authors: Kumar, Gagan; Kanthwal, Meenakshi; Chauhan, B S; Singh, M <br/> <br/>Abstract: Ferrites with general formula Mg_0.9 Mn_0.1 Fe_2-x In_x O₄, Mg_0.9 Mn_0.1 Fe_2-y Al_y O₄ and Mg_0.9 Mn_0.1 Al_0.3 Co_z Fe_1.7-z O­₄ (where <i style="">x</i>, <i style="">y</i> = 0.0, 0.1, 0.3, 0.5 and <i style="">z</i>=0.3, 0.5, 0.7) were prepared by citrate precursor technique and studied by means of X-ray diffraction and saturation magnetization. The X-ray analysis confirmed the single-phase formation of the sample. The cation distribution is inferred from the results of X-ray diffraction and magnetization measurements. <br/> <br/>Page(s): 930-934 http://nopr.niscair.res.in/handle/123456789/8391 Title: Ultrasonic velocities and refractive indices of binary mixtures of propylene carbonate + <i style="">n</i>-alkanols <br/> <br/>Authors: Wankhede, D S; Wankhede, N N; Lande, M K; Arbad, B R <br/> <br/>Abstract: The densities, ultrasonic velocities and refractive indices of binary mixtures of propylene carbonate + ethanol, <i style="">n</i>-propanol and <i style="">n</i>-butanol at 298.15, 303.15 and 308.15 K have been measured over the whole mole fraction range. Experimental data have been used to estimate the isentropic compressibility (<i style="">K_s</i>), intermolecular free length (<i style="">L_f</i>), specific acoustic impedance (<i style="">Z</i>), polarizability (<img src='/image/spc_char/alpha.gif' border=0> ) and their deviations excess isentropic compressibility (<i style="">K_s^E</i>), excess intermolecular free length (<i style="">L_f^E</i>), excess acoustic impedance (<i style="">Z^E</i>) and excess refractive index (<i style=""><img src='/image/spc_char/delta.gif' border=0>n_D</i>). The results have been fitted to Redlich-Kister equation and discussed in terms of molecular interactions. <br/> <br/>Page(s): 909-916 http://nopr.niscair.res.in/handle/123456789/8390 Title: Compensation effect of <i style="">ac </i>conduction in Se₈₀Te₂₀and Se₈₀Te₁₀M₁₀ (M = Cd, In, Sb) chalcogenide glasses <br/> <br/>Authors: Mehta, N; Kumar, D; Kumar, A <br/> <br/>Abstract: In many amorphous and liquid semiconductors and other class of materials, Meyer-Neldel rule is observed in the <i style="">dc</i> conductivity, where the pre-exponential factor (σ₀) is found to increase exponentially with the activation energy (Δ<i style="">E</i>). In the present paper, the observation of Meyer- Neldel rule in case of <i style="">ac</i> conductivity near the room temperature in bulk samples of Se₈₀Te₂₀ and Se₈₀Te₁₀M_{10<b style=""> </b>}(M = Cd, In, Sb) chalcogenide glasses has been reported. <br/> <br/>Page(s): 935-938