The ferroelectric Bi₄SrTi₄O₁₅ has been synthesized and a study of the electrical (AC) conductivity was made on both poled and unpoled samples in the frequency range from 100 Hz to 1 MHz and from room temperature to 550°C. In the case of unpoled samples the activation energy was found to be 0·54 eV and subsequent to poling it was lowered to 0·39 eV indicating an increased conductivity after poling. Further the conductivity increased with increasing frequency and temperature. DC conductivity measurements were also carried out. Dielectric measurements indicate a peak in the dielectric constant at 530°C.

Ceramic samples of Li_0·1Ba_0·95(V_xTi_1−x)O₃, wherex=0 to 0·2 were prepared by solid state reaction method. The samples were characterized by XRD. The dielectric measurements have been carried out on the sintered disks as a function of the frequency (100 Hz-1 MHz) and temperature (300–420 K). The variation of dielectric constant with temperature indicates a diffuse phase transition in all the samples studied.

Co_xCd_1−xC₂O₄4H₂O crystals grown by gel technique are characterized for dielectric properties by optical absorption measurements. Loss curve shows a relaxation peak at 500 KHz corresponding to a relaxation time of 0·3 µs. Cole-Cole diagrams give exponent of universal power law to be equal to 0·22. Optical absorption shows peaks due to Co⁺² ion and water of hydration. An attempt is made to understand the results.

An experimental setup is developed for the measurement of dynamic magnetoelectric effect (ME) in polycrystalline materials, using a time varying DC magnetic field on which an AC magnetic field is superimposed. The experimental data on ME on Bi₅FeTi₃O₁₅ and a solid solution of (90%)BiFeO₃-(10%)BaTiO₃ are obtained using this setup. The linear and higher order ME coefficients can be evaluated from the output voltage. The temperature variation of ME data gives additional information corroborating with the data on magnetization.

Pyroelectric properties of bismuth layer structured calcium substituted sodium bismuth titanate (Na_0·5Bi_0·5)_1−xCa_xBi₄Ti₄O₁₅ withx=0 (NBT) andx=0·1 (0·1 NCBT) were studied by measuring the current under short circuit condition. Spontaneous polarization and figures of merit were evaluated from the measured values of pyroelectric coefficients, dielectric constant and loss tangent. The pyroelectric properties were studied in poled and short circuit condition from 30°C to 700°C. The results obtained were discussed in the light of dielectric and conductivity properties of the samples.

Impedance of sintered discs of 0·1, 0·25, 0·4 mol% of sodium metavanadate was measured in the frequency range 10 kHz-1 MHz and in the temperature region from room temperature (=30°C) to 450°C. AC conductivity was calculated from the data. DC conductivity was measured in the temperature range 150–450°C. Debye type of relaxation effects were observed in the dielectric loss. The activation energy of the dipoles involved in relaxation was estimated. The activation energy for AC conduction in the temperature above 380°C was calculated. These values are larger than the activation energy of pure sodium metavanadate sample. The relaxation phenomenon observed is explained.