Dielectric properties of a-site deficient perovskite-type lanthanum-calcium-titanium oxide solid solution system [(1{minus}x)La{sub 2/3}TiO{sub 3}-xCaTiO{sub 3} (0.1{le}x{le}0.96)]

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(94)00142-1· OSTI ID:27976

Kim, I S; Jung, W H; Itoh, Mitsuru ^[1]

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1. Tokyo Inst. of Technology, Yokohama (Japan). Research Lab. of Engineering Materials

A solid solution system of the double perovskite La{sub 2/3}TiO{sub 3} and the GdFeO{sub 3}-type perovskite CaTiO{sub 3}, (1{minus})xCaTiO{sub 3}-xLa{sub 2/3}TiO{sub 3} has been prepared to investigate the crystal structure and the dielectric properties. In this system, the structure changed from pseudo-cubic perovskite to tetragonal double perovskite at x{approx}0.7, and to orthorhombic double perovskite at x{approx}0.9. Microwave dielectric measurement showed a decrease in dielectric constant and temperature coefficient of the resonant frequency and an increase in Q value with increasing x. The sample with x{approx}0.96 showed excellent microwave characteristics, especially high Q(2700) along with high {var_epsilon}{sub r} at 10 GHz. In the low frequency dielectric measurement, dielectric relaxation could be observed in the composition range x{le}0.3. The dielectric relaxation showed strikingly different behaviors depending on the annealing process in oxygen after sintering.

• OSTI ID: 27976
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 3 Vol. 30; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CALCIUM OXIDES
CRYSTAL STRUCTURE
DIELECTRIC PROPERTIES
LANTHANUM OXIDES
MICROWAVE EQUIPMENT
RESONATORS
TITANIUM OXIDES