Publication Date:
2013-04-11
Description:
The 0.72 Bi ( Fe 1− x Al x ) O 3 –0.28 BaTiO 3 ( x = 0, 0.01, 0.03, 0.05, and 0.07, abbreviated as BFA x – BT ) lead-free high-temperature ceramics were prepared by the conventional ceramic processing. Systematic investigation on the microstructures, crystalline structures, dielectric and piezoelectric properties, and high-temperature stability of piezoelectric properties was carried out. The crystalline structures of BFA x –BT ceramics evolve from rhombohedral structure with x 〈 0.01 to the coexistence of rhombohedral structure and pseudocubic phases with x ≈ 0.01, finally to pseudocubic phases when x 〉 0.03. Remarkably high-temperature stability with near-zero temperature coefficient of piezoelectric properties ( TCk p ), together with improved piezoelectric properties has been achieved for x = 0.01 BFA x –BT ceramics. The BFA x –BT( x = 0.01) ceramics simultaneously show the excellent piezoelectric properties of d 33 = 151 pC/N, k p = 0.31 and super-high-temperature stability of T d = 420°C, TCk p = 1 × 10 −4 . It is considered that the observed strong piezoelectricity and remarkably high-temperature stability should be ascribed to the phase coexistence of rhombohedral and pseudocubic phases. The rhombohedral phases have a positive TCk p value and the pseudocubic phases possess a negative TCk p value. Thus, the TCk p value of BFA x –BT ceramics can be tuned by composition of x .
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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