suspended_graphene Iron BiFeO3 Metal-organicComplex HOPG HighResolution ferromagnetic PMNPT PFM AM_KPFM Hole Crystal InLiquid ForceMapping MagneticPhase DiffractiveOpticalElements DataStorage Vanadate ring shape Polyethylene Alkane CrossSection Galfenol Scanning_Thermal_Microscopy AdhesionForce frequency_modulation Subhajjit Metal Nanotechnology Jason Magnetostrictive Gallium_Arsenide Polarization Leakage UnivCollegeLondon