Publication Date:
2017-05-03
Description:
This study presents the microwave dielectric properties calculation of (1- x )Ba 3.75 Nd 9.5 Cr 0.25 Nb 0.25 Ti 17.5 O 54 – x NdAlO 3 ceramics where x denotes the volume molar fraction. From X-ray diffraction results, the solid solution limit is calculated to be about 0.76, where it forms a single BaNd 2 Ti 4 O 12 phase in Region I (0 ≤ x ≤ 0.76), and both BaNd 2 Ti 4 O 12 and NdAlO 3 coexist in Region II (0.76 〈 x 〈 1). The solid solution limit is confirmed by independently calculating it from the dielectric constant data. There is less than 4% deviation between the measured dielectric constant (ε r ) and the one calculated from the Maxwell-Wagner formula. The total quality factor ( Q ) remains almost constant in Region I and increases rapidly with the volume molar fraction of NdAlO 3 in Region II. The measured Q×f , where f is the resonant frequency, is also consistent with the calculated value in both regions. The temperature coefficient at the resonant frequency is -1.4 ppm/ o C, which agrees well with the calculated value of 0 ppm/ o C. In addition, we observed a close correlation between the bulk density and the phase evolution. This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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