1：Experimental Design and Method Selection:

Solid-state reaction method was used to synthesize Bi1-xLaxVO4 ceramics. Mechanical and electrical relaxation techniques were employed to study kinetic properties, phase transition, structure change, and defect state.

2：Sample Selection and Data Sources:

High purity raw powders Bi2O3, La2O3 and V2O5 were stoichiometrically weighed and ball-milled. The mixed powders were heat treated, re-ball-milled, and then pressed into bar-shaped or disk-shaped green bodies before sintering.

3：List of Experimental Equipment and Materials:

X-ray diffraction (XRD) with Cu Kα radiation, scanning electron microscopy (SEM), low-frequency internal friction and modulus measurements using bar-shaped ceramics on a computer-controlled torsion pendulum, Precision LCR meter for dielectric properties and impedance data.

4：Experimental Procedures and Operational Workflow:

The phase of ceramics was examined by XRD. Microstructure was studied by SEM. Mechanical tests were carried out at various frequencies with the shear strain amplitude of 2.0×10-5 and the heating rate of 3 K/min. Electrical analysis was performed with polished pallet surfaces applied platinum electrodes.

5：0×10-5 and the heating rate of 3 K/min. Electrical analysis was performed with polished pallet surfaces applied platinum electrodes. Data Analysis Methods:

5. Data Analysis Methods: The internal friction and modulus data were analyzed to understand the kinetic parameters and microscopic transport mechanism. Dielectric and impedance spectroscopy studies were carried out to obtain the electric activation energy and electrical conductivity.