In-situ integrated processing and characterization of thin films of high temperature superconductors, dielectrics and semiconductors by MOCVD

In this strategy of depositing the basic building blocks of superconductors, semiconductors, and dielectric having common elements, researchers deposited superconducting films of Y-Ba-Cu-O, semiconductor films of Cu2O, and dielectric films of BaF2 and Y2O3 by metal oxide chemical vapor deposition (MOCVD). By switching source materials entering the chamber, and by using direct writting capability, complex device structures like three-terminal hybrid semiconductors/superconductors transistors can be fabricated. The Y-Ba-Cu-O superconducting thin films on BaF2/YSZ substrates show a T(sub c) of 80 K and are textured with most of the grains having their c-axis or a-axis perpendicular to the substrate. Electrical characteristics as well as structural characteristics of superconductors and related materials obtained by x-ray defraction, electron microscopy, and energy dispersive x-ray analysis are discussed

In-situ integrated processing and characterization of thin films of high temperature superconductors, dielectrics and semiconductors by MOCVD

In this strategy of depositing the basic building blocks of superconductors, semiconductors, and dielectrics having common elements, researchers deposited superconducting films of Y-Ba-Cu-O, semiconductor films of Cu2O, and dielectric films of BaF2 and Y2O3 by metal oxide chemical vapor deposition (MOCVD). By switching source materials entering the chamber, and by using direct writing capability, complex device structures like three terminal hybrid semiconductor/superconductor transistors can be fabricated. The Y-Ba-Cu-O superconducting thin films on BaF2/YSZ substrates show a T(sub c) of 80 K and are textured with most of the grains having their c-axis or a-axis perpendicular to the substrate. Electrical characteristics as well as structural characteristics of superconductors and related materials obtained by x-ray deffraction, electron microscopy, and energy dispersive x-ray analysis are discussed

Use of activated Red Mud for removal of Phosphate and Selenite from Aqueous Solutions

Red mud,a voluminous waste produced from alumina industry, mainly consist of oxides of aluminium, iron, titanium and silicon as major and oxides of calcium and sodium as minor constituents. Due to its fineness and active surface sites it can be used to absorb heavy metal ions present in industrial effluents. It is activated by different methods and used for r emoval of phosphate and selenite ions from aqueous solutions. Adsorption experiments were conducted to obtain the optimum conditions of pH, temperature, concentration of absorbate and amount of adsorbent. Applicability of Langmuir as well as Freundlich isotherms to the process was studied. Activated red mud samples produced from simple treatment with 20% HCl with and subsequent ammonia precipitation showed highest adsorption capacity for both the ions. An increase in absorption capacity with increase in adsorbate concentration and vice-versa were also observed. However, with increase in temperature, an increase in the percentage of adsorption for phosphate and decrease for selenite ions were observed. The adsorption capacity of the activated sample was correlated with the surface properties. The activated sample can be effectively used for the removal of phosphate and selenite ions from aqueous solutions

Superconducting On-chip Fourier Transform Spectrometer

The kinetic inductance effect is strongly nonlinear with applied current in NbTiN, TiN and NbN thin films. This can be utilized to realize novel devices. We present results from transmission lines made with these materials, where DC (current) control is used to modulate the phase velocity thereby enabling on-chip spectrometers. Utility of such compact spectrometers is discussed, along with their natural connection with parametric amplifiers

Red Mud Pollution Problems : Some observations

The problem of pollution caused by red mud disposal and alternatively its utilisation has remained unsolved eversince industrial production of alumina from bauxite started as a commercial venture in 1860. Indigenous efforts to utilise this collosal waste have been limited since R&D efforts in this direction lacked coordination and adequate funding. In this paper the scientific and technological approaches to tackle this problem have been discussed and few conventional as well as novel approaches are presented. While looking for economics of alumina production, ecology has totally been ignored and time has come to realign our thinking and planning process to find a tangible solution