K J Rao
Articles written in Bulletin of Materials Science
Volume 1 Issue 1 May 1979 pp 71-75 Research Communications
The dielectric behaviour of K2SO4-ZnSO4 glasses have been investigated. These glasses exhibit subglassy relaxations close to glass transition temperature. The relative dielectric permittivities exhibit sharp rise near
Volume 1 Issue 3-4 December 1979 pp 181-193
Principal features of glass transition phenomenon are summarised. Various theoretical approaches such as free volume, entropy, energy surface, etc., have been briefly discussed.
Volume 2 Issue 5 December 1980 pp 357-380
Sulphate glasses are typical ionic glasses in the sense they are constituted of discrete anions. In this review various physical properties of K2SO4, Na2SO4 and ZnSO4 glasses have been reported. A model of random close packing of ions has been suggested and used to interpret several properties including the origin of mixed alkali effect.
Volume 3 Issue 1 February 1981 pp 29-36
Densities and microhardnesses of As-Se glasses have been measured over a wide range of composition. Anomalous variations of densities and microhardnesses have been noted. It has been found possible to explain the variation on the basis of chemical ordering in these glasses. Scanning electron microscopy has been used to investigate the nature of etching in various compositions. The chemical stabilities of these glasses towards etchants also seem to support chemical ordering in them.
Volume 7 Issue 3-4 October 1985 pp 353-365
X-ray spectroscopy which is a combination of two techniques, namely x-ray absorption near edge structure (
Volume 14 Issue 2 April 1991 pp 93-94 International Conference On Superconductivity—I
Volume 14 Issue 3 June 1991 pp 531-532 International Conference On Superconductivity—II
Volume 14 Issue 4 August 1991 pp 889-890 International Conference On Superconductivity—III
Volume 15 Issue 5 August 1992 pp 389-389 Seminar On Ceramies And Glasses For Electronic Applications
Volume 15 Issue 6 December 1992 pp 481-481 Symposium Session On Rapid Solidification Processing
Volume 16 Issue 6 December 1993 pp 401-401
Volume 16 Issue 6 December 1993 pp 403-403
Volume 17 Issue 1 February 1994 pp 59-72
Several glass-ceramic compositions based on lithium silicates have been examined using thermal expansivity, X-ray diffraction, electrical conductivity, electron microscopy and solid state NMR studies. Role of P2O5 in nucleation and of Al2O3 in smoothening expansion behaviour have been particularly highlighted. Magic angle spinning NMR has been used to ascertain presence of Al in tetrahedral positions in the glassy phase.
Volume 17 Issue 6 November 1994 pp 1-
Volume 17 Issue 6 November 1994 pp 1029-1037
The local order around molybdenum and tungsten atoms in various sodium molybdophosphate and sodium tungstophosphate glasses has been investigated using extended X-ray absorption fine structure (EXAFS). Both molybdenum and tungsten atoms are present in six-coordinated environment in these glasses. Magic angle spinning nuclear magnetic resonance (MAS NMR) of31P suggests that metaphosphate or neutral [POO3/2] groups are present in these glasses.
Volume 17 Issue 7 December 1994 pp 1197-1197
Volume 18 Issue 3 June 1995 pp 301-307 Rapid Communication
Bulk AgI based fast ion conducting (FIC) glasses have been prepared by a novel microwave technique. Electrical switching characteristics of these glasses have been investigated for the first time. It has been found that AgI based FIC glasses exhibit a current-controlled high speed memory electrical switching behaviour. SEM, EDAX and ESR investigations have been performed on the virgin and switched sampies to understand the nature of the conducting state. A chemical model is proposed to explain the switching behaviour of these glasses, which is consistent with the observed results.
Volume 18 Issue 4 August 1995 pp 447-465 Indo—Japan Seminar On New Materials
An overview of the synthesis of materials under microwave irradiation has been presented based on the work performed recently. A variety of reactions such as direct combination, carbothermal reduction, carbidation and nitridation have been described. Examples of microwave preparation of glasses are also presented. Great advantages of fast, clean and reduced reaction temperature of microwave methods are emphasized. The example of ZrO2-CeO2 ceramics has been used to show the extraordinarily fast and effective sintering which occurs in microwave irradiation.
Volume 18 Issue 4 August 1995 pp 467-467
Volume 18 Issue 6 October 1995 pp 637-637
Volume 19 Issue 1 February 1996 pp 1-
Volume 19 Issue 6 December 1996 pp 1163-1165 Rapid Communication
A fast, efficient and novel method of preparation of hydroxyapatite using microwaves has been described.
Volume 22 Issue 3 May 1999 pp 139-139
Volume 22 Issue 5 August 1999 pp 843-850 India-Japan Seminar On Computational Materials Science, October 1998, Bangalore
Results of the solid-liquid transition of Ar13 cluster in a spherically symmetric external potential have been presented. The transition temperature is observed to show an elevation with pressure. The broadening of the heat capacity peaks indicate the transition becoming more diffused with pressure. The icosahedral structure of the cluster remains unaltered under pressure. Ar55 cluster has also been studied by similar approach. A possible connection between glass transition phenomenon and melting of clusters under pressure has been examined.
Volume 42 | Issue 6
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