Regensburg PFM Domain Ecoli Magnets block_copolymer plastics Gallium semifluorinated alkane Mapping Iron fluorocarbon Praseodymium MagneticForceMicroscopy nanomechanical PtfeFilter Terrace Bacteria ferromagnetic fe_nd_b LiquidCell vertical_PFM Optic dichalcogenide Lateral Ferroelectric Ca10(PO4)6(OH)2 pinpoint mode Chloroform OpticalElement CuFoil HiVacuum LateralForceMicroscopy FM_SKPM UnivOfMaryland