S H Chavan
Articles written in Bulletin of Materials Science
Volume 9 Issue 2 June 1987 pp 111-115
Second harmonic generation and temperature autostabilized nonlinear dielectric element (TANDEL) effect have been studied for ferroelectric solid solutions (Na
Volume 9 Issue 4 November 1987 pp 249-253
Pyroelectric properties of poled solid solutions of lead-barium titanate and leadstrontium titanate have been investigated in the temperature range covering their transition points. The values of pyroelectric current and coefficients of (Pb
Volume 9 Issue 5 December 1987 pp 331-336
The d.c. electrical conductivity of sodium vanadate, potassium vanadate, lithium vanadate and their solid solutions sodium-potassium vanadate, sodium-lithium vanadate were measured by a two-probe method in the temperature range covering their transition points. These materials show sharp change in conductivity at their phase transition temperatures. In sodium, potassium and lithium vanadates an exponential increase in d.c. conductivity is observed in ferroelectric region while discontinuities are observed above the transition temperatures. The activation energy in paraelectric state of the solid solutions is found to be higher than in ferroelectric state. In solid solutions the activation energy depends upon sodium vanadate concentration.
Volume 11 Issue 1 September 1988 pp 63-66
The d.c. electric field effect on ferroelectric triglycine sulphate (TGS) and TGS-Se crystals at high temperature above the Curie temperature shows the formation of a solid state battery. The current and the electromotive force of the battery are measured and their changes observed near the Curie temperature. Even if the electrodes are short-circuited the emf recovers almost to the same value.
Volume 12 Issue 1 March 1989 pp 57-62
Pyroelectric properties of Gd-doped and undoped potassium vanadate and lithium vanadate investigated in the temperature range covering their transition points show sharp increase at Curie temperature for undoped and for 0·025, 0·05, 0·1 mol% Gd2O3-doped, but no remarkable peak at Curie temperature for 0·5, 1, 3 mol% Gd2O3-doped KVO3 and LiVO3. The Curie temperature of all the samples remains the same for various concentrations of Gd.
Volume 12 Issue 2 July 1989 pp 129-132
Dielectric hysteresis properties of undoped and dysprosium-doped potassium vanadate have been studied in the temperature range covering their transition points. The coercive field of these materials was measured by the hysteresis loop method. It is observed that the coercive field of KVO3 doped with Dy2O3 at different concentrations (0 to 3 mol%) is remarkably dependent on doping concentration. It is also seen that undoped KVO3 shows ferroelectric behaviour up to 320°C while Dy2O3-doped KVO3 samples show ferroelectric behaviour up to 380°C for all concentrations.
Volume 12 Issue 2 July 1989 pp 133-136
The dielectric hysteresis property of sodium vanadate, rubidium vanadate, cesium vanadate and their solid solutions has been studied in the temperature range covering their transition points. The hysteresis loop method is used for coercive field measurements. It was observed that the coercive field decreases with increasing temperature, and that it also decreases with increasing sodium concentration in the solid solutions (sodium-rubidium) vanadate and (sodium-cesium) vanadate.
Volume 12 Issue 5 December 1989 pp 461-464
The dielectric hysteresis property of undoped and Gd2O3-doped potassium vanadate and lithium vanadate has been investigated in the temperature range covering their transition points. The hysteresis loop method has been used for coercive field measurements. The coercive field of Gd2O3-doped KVO3 and LiVO3 increases for 0·025, 0·05, and 0·1 mol %, however, it decreases for 0·5, 1 and 3 mol % of Gd2O3. It was found that the Curie temperatures of KVO3 and LiVO3 remain the same for various concentrations of Gd2O3.
Volume 13 Issue 4 September 1990 pp 301-304
Measurements of pyroelectric currents and coefficients of poled sintered discs of ferroelectric solid solutions, potassium-cesium vanadate and potassium-lithium vanadate have been investigated in the temperature range covering their transition points. In these solid solutions, K
Volume 16 Issue 4 August 1993 pp 297-302
The thermoelectric power of the vanadates of potassium, cesium and lithium and their solid solutions was measured in the temperature range covering their transition points. The thermoelectric power measurement was carried out by the two-electrode technique for pellets of polycrystalline ceramic samples. The thermoelectric power increased with temperature initially, then decreased attaining a zero value at the transition temperature. As the concentration of KVO3 increased the thermoelectric power decreased for the solid solutions (K
Volume 18 Issue 2 April 1995 pp 141-146
The temperature dependence of dc electrical conductivity was measured by two-probe technique in the vicinity of phase transition point for ferroelectrics sodium vanadate and rubidium vanadate doped with different concentrations of La2O3. These materials show a sharp change in conductivity at their phase transition temperatures. The results were found to obey the conventional exponential law and the activation energies were calculated for ferroelectric and paraelectric states. It was found that activation energy in ferroelectric phase is smaller than in the paraelectric phase. The activation energy increases slowly with increase in doping concentration of La2O3 up to 0·1 mol%, however, it decreases with further increase in doping concentration, in both ferro and para states. The dc electrical conductivity below the Curie temperature is of mixed type (ionic-electronic) while it is electronic type above the Curie temperature.
Volume 42 | Issue 6
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