Stiffness piezoelectric force microscopy MultiferroicMaterials neodymium_magnets GranadaUniv KAIST Switching NeodymiumMagnets ThermalProperties cooling Mechanical PolyvinylideneFluoride C36H74 HydroGel Melt AM-KPFM CNT FailureAnalysis vertical_PFM membrane Film Granada WPlug MonoLayer Plug F14H20 Ram Polyethylene HighAspect GaAs fe_nd_b Hydroxyapatite BCZT Corrosion block_copolymer