You can analyse SAXS curves by using chord length distribution (CLD).

See:

Angew. Chem. Int. Ed. 40 (23),  2001,4417

JACS, 126,  2004, 10535.

 You can analyse SAXS curves by using chord length distribution (CLD).

See:

Angew. Chem. Int. Ed. 40 (23),  2001,4417

JACS, 126,  2004, 10535.

Why dont you think about BET measurement of your sample for porosity? Its a very good technique..

This link may be helpful for you....

http://www.sciencedirect.com/science/article/pii/S0169772211001173

For thin films porosity and specific surface try to use ellipsometry

What is the estimated size of the porosity?

SAXS as mentioned by Juan above!

Dear Anil

For your information, you can calculate the fractional porosity in your sample was determined by Maxwell relation. But if you have a bulk density of your coating layer, can calculate your fractional porosity by using XRD diffraction analysis. Let me give you some information about this method as follows:  The bulk density of the sintered products was measured by the Archimedes displacement method. The theoretical density of the materials was calculated according to the rule of phase mixtures. Crystalline phases of the layer coating and theoretical density were identified by XRD analysis. After that you can calculate the fractional porosity by Maxwell relation when you have bulk density and theortical density from XRD analysis. I suggest, if you have the ability to form bulk sample of the same material that is used in coating, or if you have any calculation of the bulk density, then you can use this method.

For more information you can read my article as follows

Article Thermal analysis of friction welding process in relation to ...

As suggested by others, Small Angle xray spectroscopy (SAXS) is one of the extended technique of  XRD use to find nano-particle size and porosity of powder and thin film preferably in transmission mode and sometimes in reflected mode. The data are recorded in the angle range of 1-10 degree and then software is used for fitting and calculate the porosity/nano particle size.

Thank you all for your valuable guidance .

You can do X-ray density and bulk density of materials from XRD. Then we calculated Porosity (P) of materials following formula

P = (1-(bulk density/x-ray density)) x 100.

I hope this paper may helpful.

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