NOPR Collection:

Study of the interface of ZnSe/GaAs(110) heterostructures

2016-07-20T06:40:50Z

Title: Study of the interface of ZnSe/GaAs(110) heterostructures Authors: Chaudhari, G N; Manorarna, S V; Rao, V J Abstract: The different phases formed at the ZnSe/GaAs interface and Schottky barrier height have been studied by low angle X-ray diffraction, current-voltage and capacitance-voltage characteristics. It has been shown that three phases namely Ga₂Se₃, As₂Se₃and Zn₃As₂ are formed after annealing the ZnSe films on GaAs at different temperatures. The diode characteristics improved significantly and the barrier height is found to increase with increasing annealing temperature. Page(s): 215-218

Structural modelling of fractals towards electrochemical surface technology

2016-07-20T06:40:42Z

Title: Structural modelling of fractals towards electrochemical surface technology Authors: Bhatt, Devendra P; BahI, O P; Schumacher, R; Meyer, H Abstract: The fractal geometry has been considered as a powerful tool to characterize the metal solution interface in terms of the surface roughness besides having its widely published, utility in Chemistry and Physics. This paper describes the brief account on the generation of the Mandelbrot Apple-tree sets with an emphasis on deterministic and stochastic fractals and also would concentrate on the build-up of impedance diagrams of different complex equivalent circuits by viewing the surface through fractal patterns. A general simulation programme for the calculation of Nyquist plots with respect to fractal electrode-electrolyte interface has been developed and the implications of this model for electrochemical surface technology are discussed. Page(s): 207-214

Rechargeable organic batteries based on charge-transfer materials-II: Compositional dependence and charge-discharge characteristics of aromatic diamine-iodine systems

2016-07-20T06:35:21Z

Title: Rechargeable organic batteries based on charge-transfer materials-II: Compositional dependence and charge-discharge characteristics of aromatic diamine-iodine systems Authors: Singh, V K; Rao, O S; Singh, R A Abstract: The compositional and temperature dependence of various electrochemical parameters such as open-circuit voltage (V_oc), short-circuit current (I_sc) dielectric constants (ϵ) and loss factor (D) have been determined for different solid state galvanic cells based on zinc as the anode metal, charge-transfer complexes of benzidine (Bz.) and o-tolidine (o-TOL.) with iodine in different mole ratios acting as cathode and graphite or platinum as counter electrodes. The exponential decrease in electrical conductivity of these samples with time indicates that these materials are mixed ionic-electronic conductors which can be directly used for the rechargeable organic batteries. The charge-discharge characteristics of these electrochemical cells have been studied and possible explanations have been given. Page(s): 201-206

End-capping and other defects in pressed ceramic compacts

2016-07-20T06:40:29Z

Title: End-capping and other defects in pressed ceramic compacts Authors: Balakrishna, P; Chakraborthy, K P; Singh, Ajit Abstract: End-capping defect is one of the causes of rejection in pressed and sintered ceramic compacts. The causes of its occurrence lie both in the quality of the powder and that of pressing. In this paper, end-capping and other defects have been described and their relationship to powder characteristics and pressing parameters has been brought out. It is found that soft powders that are free from agglomerates, and well finished suitably tapered hard material dies and moderate compaction pressures tend to minimize end-capping and other defects. Page(s): 196-200