الفهرس 
Oxygen- and cation- deficient phasesOnly 14 pages are availabe for public view
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Abstract
The compounds of the perovskite structure ( ABO3 ) are very important material due to their useful technological applications in so many fields. They have attracted particular interest for device applications , including optical sensors, high-performance capacitors, nonvolatile memories for integrated circuit , acoustic devices and acousto-optic devices , thermistors , solid-state display and high-frequency transducers. Some of them can be used as substrate of many devices such as surface acoustic wave (SAW) filters , optical waveguides and optical switches. They , also , can be used as oxidivng or reducing catalysts. For industrial applications of complex perovskites , many systems have been developed as dielectric materials for multilayer ceramic capacitors ( MLCCs ) . Thus , in the present thesis , LaFe03 ,YFe03 and (Y1.85-u0.15)Fe03 orthoferrites ; SrCo03 and LaCoOg orthocobaltites ; tetragonal NaonW03, GaWOg and ( Na.4-G.4 )W03 bronzes ; tetragonal N%.3Mo03 and &.&lo03 bronzes , were carefidly prepared using the solid state high or moderate temperature ceramic and sintering technique. On these materials, numerous measurements were applied before and after y-absorbed dose ( 1.24 Mrad ) namely, X-ray diiaction ( XRD ), DC-electrical conductivity, UV / Vis absorption, IR absorption, Miissbauer effect and EPR. All cl~emicalsu sed were of a pure chemical grade > 99.5 % . This is to follow-up the effect of y-absorbed dose (1.24Mard) on the investigated materials.