Structure and electrical properties of (111)-oriented Pb(Mg_1/3Nb_2/3)O₃-PbZrO₃-PbTiO₃thin film for ultra-high-frequency transducer applications

Abstract

Ternary lead magnesium niobate-lead zirconate titanate system 0.4Pb(Mg1/3Nb2/3)O3–0.25PbZrO3–0.35PbTiO3 (40PMN-25PZ-35PT) thin film with a thickness of 1.5 μm was grown on Pt(111)/Ti/SiO2/Si substrate via chemical solution deposition. XRD and TEM (spell out) results suggested the film obtained was highly (111)-oriented. The remanent polarization and coercive electric field of the film were found to be 25.5 μC/cm2 and 51 kV/cm, respectively. In addition, at 1 kHz, the dielectric constant was measured to be 1960 and the dielectric loss 0.036. The film was observed to undergo a diffuse ferroelectric-to-paraelectric phase transition at around 209°C. The leakage current appeared to depend on the voltage polarity. If the Au electrode was biased positively, the leakage current was dominated by Schottky emission mechanism. When the Pt electrode was biased positively, the conduction current curve showed an ohmic behavior at a low electric field and space-charge-limited current characteristics at a high electric field.

Development of an Estimation Instrument of Acoustic Lens Properties for Medical Ultrasound Transducers

“…The acoustic lens is used to focus the ultrasound beam at the target distance and usually protects the matching layer because a medical ultrasound transducer without an acoustic lens could directly contact the target [15, 16]. The matching layer, which is one of the most important acoustic materials in the medical ultrasound transducer, is used to propagate as much ultrasound energy as possible, by matching the target medium with a piezoelectric material [17]. The piezoelectric material is used to convert electrical energy into ultrasound energy or vice versa [5].…”

An Inverse Class-E Power Amplifier for Ultrasound Transducer

“…Figure 8 a,b show the test setup and photo of the pulse-echo response when using the designed inverse Class-E power amplifier and ultrasound transducer, respectively. The test setup is a typical pulse-echo response; hence, the power amplifier and expander were used to drive the ultrasound transducer [ 83 , 84 , 85 ]. The power amplifier was located to drive the transducer before the expander circuit [ 86 ].…”