Structural and dielectric properties of substituted stannate compounds

Iftetan Ahmad Taha, . Structural and dielectric properties of substituted stannate compounds. 41-. ISSN 0128-6072

The alkaline-earth stannates having the general chemical formula MSnO 3 (MCa Sr and Ba) have been projected as potential electronic ceramics such as thermally stable capasitors humidity sensor and carbon dioxide sensor. There is no reliable technical information on the effect of substitutional doping on MSnO3 system that appears to exist in the published literature. In view of the information gaps in the reported research vigorous and systematic investigation has been carried out on two systemsSrSnO3 and MgSnO. The two systems Mg2-xMxSnO4-s where MCa and Nb and Sr1-xNxSnO3-s where NBa La and Zn have been thoroughly studied with respect to synthesis processing and characterisation-physical microstructural and electrical. Conventional solid state technique has been used in the preparation of the samples. Two sintering temparatures are employed for Mg2-xMxSnO4-s system1300 degree celcius for 24 h and 1500 degree celcius for 6h. While for Sr1-xNxSnO3-s system the sintering temperatures are 1300 degree celcius for 24 h and 1400 degree celcius for 12 h. The effect of substitutional doping and sintering temperature on the structural microstructural and dielectric properties of the two systems have been studied. The result of the X-ray diffraction analysis on the Sr1-xNxSnO3-s system revealed that single-phase solid solution has formed with Ba as substitutional element. The system has low solid solubility when substituted with La and Zn.The results of the XRD analysis on the Mg2-xMxSnO4-s system showed that a single phase solid solution has formed with Nb- Substituted sample up to x 0.05. The system has low solid solubility when substituted with Ca. Scanning electron micrographs of the samples for all compositions in the Mg2-xMxSnO4-s systems in general showed that the grains were spherical in shape and associated with some degree of porosity. In some samples even after sintering at temperature as high as 1500 degree celcius/ 6h there is still some degree of porosity. For Ca-substituted sample with x0.4 sintered at 1500 degree celcius / 6h the shape of the grains has totally changed from spherical to cubic. A thorough analysis of the measured electrical data in the frequency range of 10 superscript -2 to 10 superscript 6 Hz for Sr1-x Nx SnO3-s samples substituted with Ba and La showed that the effect of changing sintering temparature and duration from 1300 degree celcius / 24 h to 1400 degree celcius / 12 h has resulted in a decrease in the relative permittivity and loss tangent. In Nb-substituted Mg2-x Mx SnO4-s samples with 0 x 0.1 increasing sintering temperature to 1500 degree celcius / 24 h has resulted in the increase of the relative permittivity. In general low capacitance high resistance (in order of 10 superscript 9 - 10 superscript 10 ohm) and low dielectric loss were the most observed features of all compositions in the two systems under study. The equivalent circuit of Sr1-x Bax SnO3 and Sr1-xLaxSnO3-s samples with x.

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Abstract

The alkaline-earth stannates having the general chemical formula MSnO 3 (MCa Sr and Ba) have been projected as potential electronic ceramics such as thermally stable capasitors humidity sensor and carbon dioxide sensor. There is no reliable technical information on the effect of substitutional doping on MSnO3 system that appears to exist in the published literature. In view of the information gaps in the reported research vigorous and systematic investigation has been carried out on two systemsSrSnO3 and MgSnO. The two systems Mg2-xMxSnO4-s where MCa and Nb and Sr1-xNxSnO3-s where NBa La and Zn have been thoroughly studied with respect to synthesis processing and characterisation-physical microstructural and electrical. Conventional solid state technique has been used in the preparation of the samples. Two sintering temparatures are employed for Mg2-xMxSnO4-s system1300 degree celcius for 24 h and 1500 degree celcius for 6h. While for Sr1-xNxSnO3-s system the sintering temperatures are 1300 degree celcius for 24 h and 1400 degree celcius for 12 h. The effect of substitutional doping and sintering temperature on the structural microstructural and dielectric properties of the two systems have been studied. The result of the X-ray diffraction analysis on the Sr1-xNxSnO3-s system revealed that single-phase solid solution has formed with Ba as substitutional element. The system has low solid solubility when substituted with La and Zn.The results of the XRD analysis on the Mg2-xMxSnO4-s system showed that a single phase solid solution has formed with Nb- Substituted sample up to x 0.05. The system has low solid solubility when substituted with Ca. Scanning electron micrographs of the samples for all compositions in the Mg2-xMxSnO4-s systems in general showed that the grains were spherical in shape and associated with some degree of porosity. In some samples even after sintering at temperature as high as 1500 degree celcius/ 6h there is still some degree of porosity. For Ca-substituted sample with x0.4 sintered at 1500 degree celcius / 6h the shape of the grains has totally changed from spherical to cubic. A thorough analysis of the measured electrical data in the frequency range of 10 superscript -2 to 10 superscript 6 Hz for Sr1-x Nx SnO3-s samples substituted with Ba and La showed that the effect of changing sintering temparature and duration from 1300 degree celcius / 24 h to 1400 degree celcius / 12 h has resulted in a decrease in the relative permittivity and loss tangent. In Nb-substituted Mg2-x Mx SnO4-s samples with 0 x 0.1 increasing sintering temperature to 1500 degree celcius / 24 h has resulted in the increase of the relative permittivity. In general low capacitance high resistance (in order of 10 superscript 9 - 10 superscript 10 ohm) and low dielectric loss were the most observed features of all compositions in the two systems under study. The equivalent circuit of Sr1-x Bax SnO3 and Sr1-xLaxSnO3-s samples with x.

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Item Type:	Article
AGROVOC Term:	METALLIC ELEMENTS
AGROVOC Term:	ALKALINE EARTH METALS
AGROVOC Term:	DIELECTRIC PROPERTIES
AGROVOC Term:	ELECTRICAL ENERGY
AGROVOC Term:	TEMPERATURE
AGROVOC Term:	MALAYSIA ELEMENTOS METALICOS
AGROVOC Term:	METALES ALCALINOTERREOS
AGROVOC Term:	PROPIEDADES DIELECTRICAS
AGROVOC Term:	ENERGIA ELECTRICA
AGROVOC Term:	TEMPERATURA
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	24 Apr 2025 06:26
URI:	http://webagris.upm.edu.my/id/eprint/21170

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