FuelCell MESA structure Gong Liquid LFM SrTiO3 FM-KPFM lift_mode Oxide Calcite atomic_layer BiasMode PinpointPFM ScanningTunnelingMicroscopy SrO thermal_property Cell InsulatorFilm fluorocarbon MechanicalProperties high_resolution Regensburg AM-KPFM SAM ForceDistanceSpectroscopy PECurve TemperatureControllerStage Nanostructure Filter Mapping TipBiasMode Wonseok Ceramics CrystalGrowing DiffractiveOpticalElements