Piezoelectric and pyroelectric properties of Cu-doped CaBi₄Ti₄O₁₅lead-free ferroelectric ceramics

Abstract

Dense Cu-doped CaBi4Ti4O15 ferroelectric ceramics have been fabricated by a conventional ceramic technique. After doping by Cu, the ceramics become denser, and their electrical, piezoelectric and pyroelectric properties are improved. At the optimum doping level of 0.5 mol%, the ceramic exhibits a high density (6940 kg m−3), a low dielectric constant (145), a low dielectric loss (0.12%), a high resistivity (2.5 × 1013 Ω cm), a large piezoelectric coefficient (12.4 pC N−1) and a large pyroelectric coefficient (86 µC K−1 m−2). Unlike the piezoelectric properties, the pyroelectric properties, in particular those relating to the pyroelectric detection, of the ceramics are good and comparable to those of the lead-based ferroelectric ceramics. For the ceramic doped with 0.5 mol% Cu, the voltage and detectivity figures of merit for pyroelectric detection have large values of 2.6 × 10−2 m2 C−1 and 2.7 × 10−5 Pa−1/2, respectively, indicating that it is a promising candidate for pyroelectric applications.

Enhanced piezoelectric properties and excellent thermal stabilities of cobalt-modified Aurivillius-type calcium bismuth titanate (CaBi4Ti4O15)

“…These features, together with their high Curie temperature (T c ), make BLSFs attractive in high temperature and high frequency piezoelectric sensor applications. However, the piezoelectric activity (d 33 ) in BLSFs ceramics is found to be still relatively low [8][9][10][11][12][13][14][15][16], because of the difficulty in the poling process of the BLSFs ceramics which requires relatively high electric field due to the high coercive fields (Ec) and the two-dimensional orientation restriction of the rotation of the spontaneous polarization (P s ) in the BLSFs ceramics [17].…”

High performance Aurivillius type Na0.5Bi4.5Ti4O15 piezoelectric ceramics with neodymium and cerium modification

“…The mechanical quality factor Q m and the planar electromechanical coupling coefficient k p of the samples were determined by means of resonant (f r ) and anti-resonant (f a ) frequencies using an impedance analyzer (Agilent 4294A, Agilent Technology Inc., Santa Clara, CA, USA). [10,12,21,22]. It can be seen that all the ceramics are only a bismuth oxide layer-type structure with m = 4, and no secondary phases are observed in the range detected [10,12].…”

Ferroelectric Phase Transitions in Aurivillius Structure Lead-Free CaBi4Ti4O15and CaBi3.6Nd0.4Ti4O15Ceramics

“…Aurivillius structure bismuth titanate CaBi 4 Ti 4 O 15 is being regarded as promising for applications at temperatures higher than 600 K [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. It is rather difficult to prepare dense CaBi 4 Ti 4 O 15 ceramic samples as its crystal structure is highly anisotropic.…”