High Power Hydrothermal PZT Film and its Application to Transducers

研究了水热沉积PZT薄膜超声振子的高强度振动特性。结果表明，水热沉积PZT薄膜换能器在高强度振动条件下具有优越的上级特性。在块状压电材料的情况下，换能器对频率的变化具有非线性响应。而水热PZT薄膜换能器即使在高强度振动下也具有线性响应。制作了宽1 mm、长7.8mm、厚1.2mm的换能器，并对其振动特性进行了测试。在145 Vp-p的驱动电压下，采用15次沉积工艺、厚度为38 μm的PZT压电陶瓷制作的换能器振动速度为2.24 m/s，是大功率应用中PZT体材料振动速度的2倍多。此外，它接近于晶体压电材料，如3米/秒的钛酸锂换能器。看来，水热PZT h！由于它是多晶结构，因此在高强度振动工作时具有上级特性.我们研究了钛处理的预处理，使压电常数提高到原来的2倍。尝试了一种新的电极化学法工艺。在短时间内得到大量的沉积。这一点需要进一步调查。也尝试了声化学方法，但需要深入研究。

High intensity vibration characteristics of the hydrothermaly deposited PZT thin film ultrasonic vibrator was examined. It was found that the hydrothermal deposition PZT film transducer had the superior characteristics at high intensity vibration condition. In case of bulk piezoelectric material, the transducer has non linear response against the variation of the frequency. However, the hydrothermal PZT film transduecer had linear response enven in high intensity vibration operation. We fabricated a transducer whose dimenstions were 1 mm wide, 7.8 mm long and 1.2 mm thick, then vibration characteristics was measured. The transducer which was 15 times deposition process and 38 μm PZT thick produced 2.24 m/sec vibration velocity at the driving voltage of 145 Vp-p. This value was more than 2 times of a bulk PZT material for high power application. Moreover, it was close to a crystal piezo material such as litium niobate transducer of 3 m/sec. It seems that the hydrothermal PZT h!as poly crysital structure, hence it has superior characteristics at high intensity vibariton operation.we examined the preprocess of the titanium treatment, then the piezoelectric constant was improved up to 2 times of the previouse one. A novel process of elector chemical method was tried. Large amount of deposition was obtained in short time reaction. Farther investigation is required for this point. Sonochemical method was also tried, but it requires deep investigation.