MonoLayer BariumTitanate Barium_titanate PetruPoni_Institute ContactModeDots Singapore Led Microchannel PUR thermal_conductivity IMT_Bucharest EFMAmplitude Ptfe temperature controller AFM flakes UnivCollegeLondon MBE EFM YszSubstrate sputter Array VerticalPFM LaAlO3 University_of_Regensburg Multiferroic_materials Metal-organicComplex Self-assembledMonolayer Hexylthiophene mechanical_property HiVacuum Sidewall Insulator Holes Nanotechnology molecule