Permalloy Iron Electrical&Electronics Metal-organicComplex FrictionalForce Boundary Polyimide PFM Modulus NUS_NNI_Nanocore Vac #Materials Singapore LiftHeight 2-vinylpyridine EFM tip_bias_mode Optoelectonics ferromagnetic Pinpoint PFM chemical_compound Edwin Electronics SAM Polyvinylidene_fluoride BismuthFerrite Annealed GaN temp Roughness align temperature_control UTEM CastIron Gong