Low loss Sr{sub 1-x}Ca{sub x}La{sub 4}Ti{sub 5}O{sub 17} microwave dielectric ceramics
- Materials Research Laboratory, Institute of Physics and Electronics, University of Peshawar, Post Code 25120 (Pakistan)
Highlights: {yields} New single phase highly dense (95%) microwave dielectric Sr{sub 1-x}Ca{sub x}La{sub 4}Ti{sub 5}O{sub 17} (0 {<=} x {<=} 1) ceramics were designed and processed. {yields} Theoretical density and molar volume decreased due to the substitution of small Ca{sup 2+} for large Sr{sup 2+}. {yields} As required for microwave dielectric applications, optimum properties (i.e. {epsilon}{sub r} {approx} 53.7, Qf{sub o} {approx} 11,532 GHz and {tau}{sub f} {approx} -1.4 ppm/{sup o}C) were achieved for Sr{sub 0.4}Ca{sub 0.6}La{sub 4}Ti{sub 5}O{sub 17} (x = 0.6). -- Abstract: Microwave dielectric ceramics in the Sr{sub 1-x}Ca{sub x}La{sub 4}Ti{sub 5}O{sub 17} (0 {<=} x {<=} 1) composition series were prepared through a solid state mixed oxide route. All the compositions formed single phase ceramics within the detection limit of in-house X-ray diffraction when sintered in the temperature range 1450-1580 {sup o}C. Theoretical density and molar volume decreased due to the substitution of Ca{sup 2+} for Sr{sup 2+} which was associated with a decrease in the dielectric constant ({epsilon}{sub r}) and temperature coefficient of resonant frequency ({tau}{sub f}) but an increase in quality factor, Qf{sub o}. Optimum properties were achieved for Sr{sub 0.4}Ca{sub 0.6}La{sub 4}Ti{sub 5}O{sub 17} which exhibited, {epsilon}{sub r} {approx} 53.7, Qf{sub o} {approx} 11,532 GHz and {tau}{sub f} {approx} -1.4 ppm/{sup o}C.
- OSTI ID:
- 22212190
- Journal Information:
- Materials Research Bulletin, Vol. 46, Issue 7; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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