1：Experimental Design and Method Selection:

The ceramics were prepared using a mixed-oxides method according to the nominal formula (Ba1?xHox)(Ti1?xHox)O3 (x = 0.01, 0.02, 0.03, 0.04, 0.05, and 0.10) (BHTH). The mixture was calcinated in air at 1100 °C for 5 h for decarbonation, then pressed into pellets and sintered at 1400 °C for 12 h in air.

2：01, 02, 03, 04, 05, and 10) (BHTH). The mixture was calcinated in air at 1100 °C for 5 h for decarbonation, then pressed into pellets and sintered at 1400 °C for 12 h in air. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Initial materials were re-agent BaCO3 (99.4%), TiO2 (99.5%), and Ho2O3 (99.9%) powders.

3：4%), TiO2 (5%), and Ho2O3 (9%) powders. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: X-ray diffractometer (DX-2700, Dandong Haoyuan), Raman spectrometer (LabRAM XploRA, Horiba Jobin Yvon), scanning electric microscope (EVOMA 10, Zeiss), Dielectric/Impedance spectrometer (Concept 41, Novocontrol), Precision Premier II system (Radiant Technologies), ZJ-4AN quasi-static d33 meter (The Institute of Acoustics of the Chinese Academy of Sciences), A300-10/12 X-band spectrometer (Bruker).

4：Experimental Procedures and Operational Workflow:

The mixture was calcinated, pressed into pellets, sintered, and then characterized using XRD, SEM, PL, EPR, and dielectric measurements.

5：Data Analysis Methods:

Pawley refinement was performed with the Accelrys MS Modeling software to determine the unit-cell volume and lattice parameters. The dielectric properties were analyzed using the Curie-Weiss law.