TY - JOUR A1 - Lacasa, Jesús S. A1 - Almonte, Lisa A1 - Colchero, Jaime T1 - In situ characterization of nanoscale contaminations adsorbed in air using atomic force microscopy JF - Beilstein Journal of Nanotechnology PY - 2018/// VL - 9 SP - 2925 EP - 2935 SN - 2190-4286 DO - 10.3762/bjnano.9.271 PB - Beilstein-Institut JA - Beilstein J. Nanotechnol. UR - https://doi.org/10.3762/bjnano.9.271 KW - atomic force microscopy KW - cantilever KW - contact potential KW - electrostatic forces KW - force spectroscopy KW - Hamaker constant KW - Kelvin probe microscopy KW - surface contamination KW - tip cleaning KW - tip–sample interaction KW - van der Waals interaction N2 - Under ambient conditions, surfaces are rapidly modified and contaminated by absorbance of molecules and a variety of nanoparticles that drastically change their chemical and physical properties. The atomic force microscope tip–sample system can be considered a model system for investigating a variety of nanoscale phenomena. In the present work we use atomic force microscopy to directly image nanoscale contamination on surfaces, and to characterize this contamination by using multidimensional spectroscopy techniques. By acquisition of spectroscopy data as a function of tip–sample voltage and tip–sample distance, we are able to determine the contact potential, the Hamaker constant and the effective thickness of the dielectric layer within the tip–sample system. All these properties depend strongly on the contamination within the tip–sample system. We propose to access the state of contamination of real surfaces under ambient conditions using advanced atomic force microscopy techniques. ER -