1：Experimental Design and Method Selection:

The Ba(Ti

2：92Sn08)O3 ceramic was prepared by the traditional solid-state synthesis route. High purity TiO2, SnO2 and BaCO3 powders were milled, calcined, pressed into disks, and sintered. Silver electrodes were pasted for electrical measurements. The poling process was performed under an electric field. Sample Selection and Data Sources:

The phase structure was analyzed by X-ray diffraction and Raman spectrum. The microstructure was investigated by FE-SEM and TEM. The piezoelectric coefficient d33 was characterized by a Berlincourt meter. The planar electromechanical coupling coefficient kp was measured by a precision impedance analyzer. A piezo-measurement system was employed for various ferroelectric and piezoelectric measurements.

3：List of Experimental Equipment and Materials:

X-ray diffraction (D8-2-Advance, Bruker AXS, Germany), Raman spectrum (Lab RAM HR Evolution, Horiba JY, France), FE-SEM (JSM-7500, Japan), TEM (Tecnai G2 F20 S-TWIN), Berlincourt meter (ZJ-3A, China), impedance analyzer (HP 4294A, Agilent, USA), piezo-measurement system (TF Analyzer, 2000HS, aix ACCT Systems GmbH, Aachen, Germany).

4：Experimental Procedures and Operational Workflow:

The samples were prepared, sintered, and characterized for their structural, microstructural, and piezoelectric properties. The temperature dependence of dielectric properties was examined.

5：Data Analysis Methods:

The data were analyzed to understand the phase transitions and their effects on piezoelectric properties.