gallium_nitride Ram ScanningSpreadingResistanceMicroscopy VinylAlcohol BiasMode SPMLabs TiO2 DiffractiveOpticalElements self-assembled_monolayer HighResolution mfm_amplitude Hexatriacontane Ca10(PO4)6(OH)2 P3HT Resistance Modulus Cobalt-dopedIronOxide Vanadate Polymer PinpointNanomechanicalMode SICM membrane chemical_compound Hexacontane Vinylpyridine #EC EPFL KPFM Conductive AFM MultiferroicMaterials Korea AmplitudeModulation WPlug ElectroChemical Aggregated_molecules