ELECTRIC PROPERTIES OF CERTAIN SOLID SOLUTIONS OF NIOBATES AND TANTALATES OF BIVALENT METALS (in Russian)
Three-component systems of lead and alkaline-earth niobates were prepared, replacing partially the niobium by tantalum, in order to establish the influence of the replacement on the ferroelectric properties of the system. The general composition of the solid solutions is given by the formulas: (Pb/sub 0.5/ Ba/sub 0.1/Sr/sub 0.4/ (Nb/sub 1-/ >i/sub x/Ta/sub x/)/sub 2/O/sub 6/ and (Pb/ sub 0./ /sub 6/Ba/sub 0./ /sub 2/Ca/sub 0./ /sub 2/) (Nb/sub 1-x/Ta/sub x/ >i)/ sub 2/O/sub 6/, using Ba, Ca, and Sr carbonates, PbO, and Nb/sub 2/O/sub 5/ and Ta/sub 2/O/sub 5/ as raw materials. The usual ceramic preparative methods were employed, firing the compounds containing large amounts of tantalum under an inert atmosphere. X-ray diffraction studies of the systems showed that their structure is similar to that of the orthorhombic lead niobate. In view of this and of the near-identity of the ionic diameters of Nb/sup 5+/ and of Ta/sup 5+/, it could not be established with certainty whether the systems were solid solutions or heterogeneous mixtures. No hysteresis loops were observed at liquid nitrogen temperatures with materials having relaxation properties, not even with systems with an x value?0.3 which presented such loops at room temperature, which may be explained by the increase of the coercive field at low temperatures. The replacement of niobium by tantalum led first to a weakening of the ferroelectric properties, followed by emergence of relaxation properties. (TTT)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-15-007336
- OSTI ID:
- 4117989
- Journal Information:
- Izvest. Akad. Nauk S.S.S.R., Ser. Fiz., Vol. Vol: 24; Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- Country unknown/Code not available
- Language:
- Russian
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