1：Experimental Design and Method Selection:

The study uses pulsed laser deposition (PLD) to deposit BCFZY thin films due to its ability to preserve the composition and molecular structure of the target material. The overall design involves synthesizing BCFZY powder, pelletizing it into a target, and depositing it via PLD onto substrates for characterization and fuel cell testing.

2：Sample Selection and Data Sources:

BCFZY powder is synthesized from precursor powders (Ba(NO3)2, Co(NO3)2?H2O, FeN3O9?9H2O, ZrO(NO3)2, Y(NO3)3?6H2O) using a sol-gel method. The target is made by pressing and sintering the powder. Thin films are deposited on Si wafers and ScSZ pellets for analysis.

3：List of Experimental Equipment and Materials:

Equipment includes a hot plate, dry oven, ball mill with YSZ balls, hydraulic laminating press, PLD system (DUAL multi-layer PLD system, Higgslab Co., Ltd), KrF excimer laser (Lambda Physik, Coherent Co.), XRD (X’pert pro, PANalytical Co.), FIB-SEM (3D FEG, FEI Co.), FE-SEM (SUPRA 55VP, Carl Zeiss Co.), EDS (Bruker Co), sputtering system (A-Tech System Ltd), SOFC test station, electrical furnace (Korea Furnace Development Co.), and potentiostat (Reference 600, Gamry Instruments). Materials include precursor chemicals, EDTA, citric acid, ammonia, isopropyl alcohol (IPA, Daejung chemistry Co.), YSZ balls (MTI Korea Co.), and ScSZ pellets (Fuel Cell Materials Co.).

4：Experimental Procedures and Operational Workflow:

BCFZY powder synthesis via sol-gel with chelating agents, carbonization, ball-milling, drying. Target fabrication by pressing at 60 MPa and sintering at 1100°C. PLD deposition with parameters: laser energy density 190 mJ, substrate temperature 600°C, target-surface distance 7.8 cm, deposition time 1 hour, pulse speed 6 pulses/s. Characterization using XRD, FIB-SEM, FE-SEM, EDS. SOFC fabrication by sputtering Ni anode on ScSZ pellet, depositing BCFZY cathode via PLD, grinding edges to prevent shorting. Testing at 500°C with hydrogen flow and air exposure, monitoring OCV for 1 hour.

5：8 cm, deposition time 1 hour, pulse speed 6 pulses/s. Characterization using XRD, FIB-SEM, FE-SEM, EDS. SOFC fabrication by sputtering Ni anode on ScSZ pellet, depositing BCFZY cathode via PLD, grinding edges to prevent shorting. Testing at 500°C with hydrogen flow and air exposure, monitoring OCV for 1 hour. Data Analysis Methods:

5. Data Analysis Methods: XRD analysis to confirm perovskite structure with scan angle rate 2.0°/min and step 0.02°. SEM and EDS for morphological and elemental analysis. OCV measurement using potentiostat to assess fuel cell performance.