KPFM BFO CrAu AM-KPFM PetruPoni_Institute MESA structure ScanningKelvinProbeMicroscopy Lift amplitude_modulation Oxidation Magnets STM BismuthFerrite ScanningThermalMicroscopy temperature_control Ceramics BiVO4 single_layer Alkane Bacteria sputter PhaseImaging HighAcpectRatio GaAs VerticalPFM FAPbI3 Collagen Heating MolybdenumDisulfide Gallium_Arsenide MoS2 Pinpoint lithography NTU Stiffness