3-hexylthiophene CopperFoil ForceDistanceSpectroscopy Nanostructure Ptfe Tapping chemical_compound DomainSwitching Singapore Vinylpyridine Film Polarization frequency_modulation SingleCrystal Scanning_Thermal_Microscopy VortexCore HOPG temp Phthalocyanine PyroelectricDetector FastScan WS2 Jason Layer ThermalConductivity domain_switching Sapphire BFO NeodymiumMagnets Nanofiber pulsed_laser_deposition Scratch SKKU Cross-section IRDetector