Electrical properties of Li doped sodium potassium niobate thick films prepared by a tape casting process

(100)-Textured KNN-based thick film with enhanced piezoelectric property for intravascular ultrasound imaging

“…2(c), under the electric field of 50 kV/cm, the induced strain of textured KNLN film can attain 0.075%. This value is much larger than those results for other KNN thick films at the same electric field, 11,13,14 which is attributed to its high orientation structure and no substrate clamping effect. In a bid to get the longitudinal piezoelectric coefficient of d 33 of the textured KNLN thick film, a dual-beam laser interferometer was utilized and the applied ac electric field was 5 kHz with the amplitude of 0.1 kV/cm.…”

“…The measured d 33 of $150 pm/V is superior to other KNN thick films [9][10][11][12][13][14] and is comparable to lead-based films, 17 indicating that the obtained KNLN thick film possess the capability for ultrasound transducer applications.…”

“…Given that lapping down bulk material to the desired thickness is also a time-consuming and difficult task, lead-free piezoelectric thick films apparently are a promising alternative. Although much effort has been devoted to the exploration of lead-free thick films in recent years, [9][10][11][12][13][14] no one has been reported to be competent for IVUS (>50 MHz) transducer application yet. With this in mind, it would be interesting and worthy to investigate the possibility of IVUS imaging utilizing lead-free piezoelectric thick films at higher frequency (>50 MHz).…”

Small Reduction of the Piezoelectric d33 Response in Potassium Sodium Niobate Thick Films

“…An unmodified KNN bulk ceramic was reported to have a piezoelectric d 33 coefficient between 80 and 120 pC/N. In general, the processing and functional properties of KNN thick films have been studied to a much lesser extent [9][10][11][12][13][14][15][16] in comparison with KNN thin films and bulk ceramics. 7 Taking into account their other properties, for example, density, longitudinal sound velocity, dielectric constant, mechanical, and dielectric losses, Tran-Huu-Hue et al 8 reported that KNN materials are suitable for high-frequency applications.…”

Enhanced piezoelectric properties of solution-modified Ba(Zr0.2Ti0.8)O3–(Ba0.7Ca0.3)TiO3 thick films

“…In recent years, the fabrication of piezoelectric thick films with thicknesses ranging from 1 to 100 lm has become an urgent demand for applications in tiny microdevices such as microelectromechanical systems (MEMS) due to the drive for miniaturization, high power/sensitivity, and system integration [1,2]. Currently, some efforts have been made to improve the properties of typical lead-free piezoelectric thick films, such as bismuth sodium titanate (BNT) [3,4] and potassium sodium niobate (KNN) [5][6][7] thick films, but their piezoelectric constants are still low (d 33 % 100 pC/N) compared with that in PZT thick films (d 33 % 200 pC/N) [1]. Recently, Liu and Ren has reported a lead-free (1 À x) Ba(Zr 0.2 Ti 0.8 )-O 3 -x(Ba 0.7 Ca 0.3 )TiO 3 (abbreviated as BZT-xBCT) piezoceramics with the composition near the morphotropic phase boundary (MPB) that show excellent piezoelectric properties with d 33 % 600 pC/N, which is comparable even with that of high-end PZT ceramics [8].…”