Microscope having a multimode local probe, tip-enhanced raman microscope, and method for controlling the distance between the local probe and the sample

摘要

A multimode local probe microscope having a resonator, a first electrode, and a second electrode, an excitation source adapted to generate mechanical resonance in the resonator, a metal tip fastened to the resonator, movement mechanism for imparting relative movement between the local probe and a sample and adapted to bring the end of the tip to within a distance Z lying in the range 0 to 100 nm, and detector for detecting at least one electrical signal representative of friction forces at the terminals of said electrodes. The metal tip is electrically connected to the output second electrode and the microscopy apparatus includes amplifier and filter for amplifying and filtering signals relating to the friction forces and to the tunnelling current in a single electronic circuit, and configured for regulating the distance Z between the end of the tip and the surface of the sample.

主权项

1. A multimode local probe microscope comprising:
a resonator having an input first electrode and an output second electrode arranged on the resonator; excitation mechanism adapted to generate mechanical resonance in the resonator; a metal or metal-plated tip having an end of nanometer dimensions, the tip being fastened to the resonator; and movement mechanism for imparting relative movement between the resonator and a sample, the movement being adapted to bring the end of the tip up to a distance Z lying in the range 0 to 100 nm from the surface of the sample; wherein: said tip is electrically connected to said output second electrode, said output second electrode forming a common electrical contact point for collecting firstly a first electrical signal representative of friction forces between the end of the tip and the surface of the sample, and secondly a second electrical signal relating to a tunnelling current between the end of the tip and the surface of the sample; and in that the microscope includes: amplifier electrically connected to said output second electrode, said amplifier being adapted to amplify the second signal relating to the tunnelling current; processor adapted to process separately firstly the first signal relating to friction forces and secondly the second signal relating to the tunnelling current; and regulator adapted to regulate the distance Z between the end of the tip and the surface of the sample, regulation in a first mode being as a function of the first signal representative of friction forces, and regulation in a second mode being as a function of the second signal relating to the tunnelling current.