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Eleven glass compositions were prepared by melt and quench method with progressive substitution of SrO for PbO (0 ≤ x ≤ 1•0) with a step-wise increment of 0•10 in the glass [(Pb x Sr 1−x)OTiO 2 ]-[(2SiO 2 B 2 O 3)]-[BaO•K 2 O]•Nb 2 O 5 (mol percentage) system. The infrared spectra (IR) of various glass compositions in the above mentioned glass system was recorded over a continuous spectral range 400-4000 cm −1 to study their different oxides structure systematically. Differential thermal analysis (DTA) was recorded from room temperature (∼27 • C) to 1400 • C employing a heating rate of 10 • C/min to determine glass transition temperature, T g and crystallization temperature, T c. The melting temperature, T m , of these glass compositions was found to be in the range 597-1060 • C depending on the composition under normal atmospheric conditions. T g and T m of glasses were found to increase with increasing SrO content. X-ray diffraction analysis of these glass-ceramic samples shows that major crystalline phase of the glass-ceramic sample with x ≤ 0•5 was found to have cubic structure similar to SrTiO 3 ceramic. Scanning electron microscopy has been carried out to see the surface morphology of the crystallites dispersed in the glassy matrix. Keywords. (PbSr)TiO 3 borosilicate glasses; infrared spectroscopy; DTA; XRD and SEM.

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The systematic study on structural properties of Ba-substituted La0.9Sr0.1Al0.9Mg0.1O3–δ and its correlation with conductivity was carried out. X-ray diffraction patterns indicated that the system formed a single phase composition up to 3% of Ba double substitution at the La-site. Energy dispersive X-ray spectroscopy and XPS results confirmed elemental compositions and revealed the maximum deficiency in oxygen for the 3% Ba-substituted sample. Dense grain formation is observed in SEM images, complementing higher density of these samples (>93%). Electrical conductivity was found to be in correlation with a new structural parameter of the critical triangle of (La/Sr/Ba)-Al/Mg-(La/Sr/Ba). The value of conductivity increased by an order of 2 in a substituted sample as compared to pure LaAlO3. The activation energy can be correlated with the area of the critical triangle of (La/Sr/Ba)-Al/Mg-(La/Sr/Ba). The migration path for ionic conduction of the oxygen ion was mapped out using the correlation of bulk conductivity with the A-A-B angle (β) and dc conductivity with the A-B-A angle (α).

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Samples in the system SrSn 12x Ti x O 3 were prepared by conventional solid state ceramic route for 0(x(0?50. Powder X-ray diffraction was performed to confirm formation of single phase solid solution. It has been found that solid solution forms only up to x50?40. DC resistivity and Seebeck coefficient a were measured to understand electrical conduction behaviour. It has been observed that in all the compositions electrons are the major charge carriers. Scanning electron micrographs were taken to study the microstructure. It has been found that grain size is in the range of 1-5 mm. Based on the results of a and activation energy E a of DC conduction, it is proposed that conduction occurs due to migration of O 22 ions through oxygen vacancies V 00 O for all the compositions.

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