Workfunction Water FM-KPFM frequency_modulation margarine atomic_steps China Fujian Stiffness Oxidation alkanes Sadowski piezoelectric force microscopy molecular_beam sputter EFMAmplitude ContactModeDot PMNPT Writing Anneal Pore OpticalWaveguide SiliconOxide ScanningKelvinProbeMicroscopy MultiferroicMaterials conductive SetpointMode InsulatorFilm AAO VortexCore Aluminium_Oxide AmplitudeModulation Phthalocyanine Topography BiVO4