Oxidation ScanningKelvinProbeMicroscopy Heat StrontiuTitanate PtfeMembrane Polytetrafluoroethylene Hydroxyapatite CrossSection temp EFM HfO2 Formamidinium_lead_iodide Writing BTO Water Annealing SSRM MagneticForceMicroscopy Ferrite Moire biocompatible Adhesive Photovoltaics Gong BismuthFerrite Butterfly ferromagnetic CalciumHydroxyapatite piezoelectric force microscopy nanobar FM-KPFM EPFL Wafer frequency_modulation blended polymers