US 9,316,668 B2 · Determination of local contact potential difference by noncontact atomic force microscopy

Abstract

A method for determining a value of a local contact potential difference by noncontact atomic force microscopy. For one or more cantilever positions above a surface of a sample: i) performing two atomic force microscopy measurements, using an oscillating cantilever, ii) thereby determining two distinct voltage values of DC voltage applied between the cantilever and the sample, and iii) obtaining a value of a local contact potential difference based, at least in part, on the two distinct voltage values determined. Wherein substantially similar distinct values indicate a substantially similar value of frequency shifts of cantilever oscillation, as measured for each of said distinct values.

Claims15

Dependent claims

A method for determining a value of a local contact potential difference by noncontact atomic force microscopy, the method comprising:

for one or more cantilever positions above a surface of a sample:
performing two atomic force microscopy measurements, using an oscillating cantilever, thereby determining two distinct voltage values of DC voltage applied between the cantilever and the sample, wherein substantially similar distinct values indicate substantially similar values of frequency shifts of cantilever oscillation, as measured for each of said distinct values;
and
obtaining a value of a local contact potential difference based, at least in part, on the two distinct voltage values that were determined.

1 more element

An atomic force microscopy apparatus, configured for performing atomic force microscopy measurements using an oscillating cantilever, the apparatus comprising:

a frequency shift measurement unit configured for measuring a frequency shift of cantilever oscillation;
a circuit connected to the frequency shift measurement unit, the circuit being configured to:
determine a DC voltage to be applied by the apparatus between a cantilever and a sample for an AFM measurement;
and
adjust such a DC voltage such that a value of a frequency shift, as measured by the frequency shift measurement unit, matches a reference frequency shift;
a memory that is configured to store one or more pairs of distinct values of DC voltages that correspond to a same value of frequency shift of cantilever oscillation;
and
a processor connected to the memory to access said one or more pairs of voltage values, the processor being configured to determine values of local contact potential differences based, at least in part, on said one or more pairs.

5 more elements

Dependencies are inferred from the claim text.

Determination of local contact potential difference by noncontact atomic force microscopy

Life of this patent

Determination of local contact potential difference by noncontact atomic force microscopy

Life of this patent

Abstract

Claims15