Structure and dielectric properties of Nd substituted Bi sub(1.5)MgNb sub(1.5)O sub(7) ceramics

• Published in: Journal of materials science. Materials in electronics Vol. 24; no. 8; pp. 2785 - 2789
• Main Authors: Huang, Baoshuai, Liu, Yunfei, Lu, Yinong, Gao, Hong, Chen, Hu
• Format: Journal Article
• Language: English
• Published: 01.08.2013
• Subjects: Ceramics; Coefficients; Dielectric constant; Dielectric properties; Dielectrics; Neodymium; Pyrochlores; Scanning electron microscopy
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-013-1171-9

New pyrochlore ceramics Bi sub((1.5-x))Nd sub(x)MgNb sub(1.5)O sub(7) with x = 0-0.6 were synthesized by doping Nd into the A site in the Bi sub(1.5)MgNb sub(1.5)O sub(7) pyrochlore. The Nd substituted Bi sub(1.5)MgNb sub(1.5)O sub(7) ceramics were prepared utilizing solid-state reaction and investigated by X-ray diffraction, scanning electron microscope and dielectric measurements. The crystal structure was characterized as single cubic pyrochlore phase for x less than or equal to 0.5 while the second phase appeared at x = 0.6. With increasing Nd content from 0 to 0.5, the lattice parameters decreased slightly and the average grain size pronouncedly reduced from ~7.5 to ~5.0 mu m. The Nd incorporation resulted in attractive enhancement of the dielectric properties including the temperature coefficient of dielectric constant that was remarkably optimized with the lowest value of -16 ppm/ degree C at x = 0.5. A good combination of low dielectric loss, superior temperature coefficient and high dielectric permittivity can be achieved for the composition of x = 0.5, which seems to be very appealing for the practical use in high-frequency multilayer ceramic capacitors.