1：Experimental Design and Method Selection:

The study involved the development of a BiT/ST sol-gel composite for ultrasonic transducers. The methodology included the fabrication of ST sol-gel solution, mixing with BiT powder, and fabrication of composite films on titanium substrates using sol-gel spray technique. Polarization processes were carried out at room temperature and 400°C. High temperature durability tests were performed from room temperature to 500°C.

2：Sample Selection and Data Sources:

Commercial BiT powder and self-manufactured ST sol-gel solution were used. The samples were fabricated on titanium substrates.

3：List of Experimental Equipment and Materials:

Equipment included a digital oscilloscope, pulser/receiver machine, hot plate, and XRD for analysis. Materials included strontium acetate, titanium butoxide, acetic acid, methanol, and BiT powder.

4：Experimental Procedures and Operational Workflow:

The ST sol-gel solution was fabricated by dissolving strontium acetate in deionized water, then adding to a mixture of titanium butoxide, acetic acid, and methanol. The mixture was ball milled for homogeneity. Films were fabricated by spray coating, followed by drying and firing processes. Polarization was performed using DC corona poling.

5：Data Analysis Methods:

Ultrasonic response was recorded and analyzed. Sensitivity was calculated to assess performance at various temperatures.