Vadim Thanks for your kind reply. Can it be done by nanoindentation or AFM?

Md Amir

In remote force spectroscopy, f-d curves were used to measure the force that the AFM cantilever exerted on a single point on the sample surface. The F-d curves are plots of cantilever bend (measured with a position-sensitive photodetector) versus piezoelectric scanner displacement.

Volumetric force mapping is based on remote force spectroscopy: in this method, a data array containing the value of the force at each measured point is converted into a two-dimensional hardness map (in this case, the resistance to local plastic deformation during indentation with a cantilever) of the entire surface of the studied sample area . Here hardness is defined as the slope of the f-d curve and is measured in N/m.

The shape of these curves corresponds to the measured physical interaction between the cantilever and the sample, which, in this case, is expressed as the dependence of the distance between the cantilever and the sample on the force effect of the cantilever on the sample surface. Thus, the slope of the f-d curve is steeper when the cantilever is pressing on a harder area of ​​the sample.

Dear Md Amir ,

AFM or nanoindenter can help for this purpose. It depends on the size of the particle. AFM tipically is easier to find and indent on smaller particles, (below 100 nm) while nanonindenter is better if the NP's are bigger.

For example this free software:

Article AtomicJ: An open source software for analysis of force curves

Allows you to open F-D curves obtained by AFM and calculate the modulus with different contact mechanics models.

However the most difficult part is always how to prepare the sample so that you can easily find the NP's and more importantly, they are well fixed to the surface so that they do not move while you are doing the indentation.

there 3 main methods:

1- by using the AFM Single Molecule Force Spectroscopy (SMFM), use SEM to find the suitable concentration and conditions (best diluted ratio to avoid aggregation) to be ready for Single force spectroscopy process then force distance curves of the cantilever and the Young’s Modulus can be calculated

Repeat the measurements process many times for each NP and for many NPs.

more details here: Elastic Properties of Polystyrene Nanospheres Evaluated with Atomic Force Microscopy: Size Effect and Error Analysis | Langmuir (acs.org).

2- by using FTIR curve, more details here: Article Elastic properties of nanocrystalline aluminum substituted n...

3- by using Raman and Mossbauer Spectroscopy and X‑ray Diffractometry, more details here: DOI: 10.1021/ic502497a.