ContactModeDot Metal MagneticArray Ito Patterns Wonseok Array EFMAmplitude Butterfly BiFeO3 Collagen EFM semifluorinated alkane Chungnam_National_University SiWafer frequency_modulation Nickel Graphene FM_KPFM Magnetic Force Microscopy Modulus AAO hard_disk_media CNT MolecularSelfAssembly Hafnium_dioxide Ceramic InorganicCompound OrganicSemiconductor NCM\ Wildtype HighAcpectRatio lithography Yeditepe_University Polyaniline