THE MEASUREMENT OF THE METAL PARTICLE NANOSIZE 

N.  Aldea1, B. Barz1 , P.Marginean1, Xie Yaning2, Hu Tiandou2, Liu Tao2, Zonghua Wu2 and  Florica Aldea3

1National Institute of Research and Development for Isotopic and Molecular Technologies,  R-400293 Cluj-Napoca, P.O. 5, Box 700, Romania
2 Beijing Synchrotron RadiationFacilities of Beijing Electron Positron Collider National Laboratory, Beijing, People's Republic of China
3 Agriculture and Veterinary Medicine University, Cluj-Napoca, Romania
		
The reasons for studying the metal particle nanosize are not few and we mention only some of them: the strong correlation between the catalytic activity and the particle size, within this field of “nanomaterials” the physics and chemistry concepts undergo modifications with applications in spin electronics, in order to produce nanotechnologies it is necessary to know the nanostructure of the metal particles. 
Besides chemosorbtion of the hydrogen, magnetization measurements, transmission electron microscopy methods, X-ray line diffraction profile (XRLP) analysis one can obtain crystallite size and microstrain. The main part of the paper presents different analytical approximations used in the theory of the XRLP analysis, including Charlson, Warren - Averbach and general approximations. A detailed mathematical treatment is realised on the convolution product of two pseudoVoigt (PV) and generalised Fermi (GFF) functions respectively [1,2].
The powder X-ray diffraction is the cheapest method that gives the most results (average crystallite size, microstrain, stacking fault probability). It is important to have a good S/N ratio, a reliable deconvolution of the experimental and the instrumental spectra and an adequate package program. All algorithms are implemented in XRSIZE computer package programs written in Maple symbolic language.
The complete structural results based on the XRLP analysis of the supported catalysts as follows: Au/SiO2, Au/MTA, Au/Al2O3, Ni/SiO2, Ni/MTB1, mathematical models and XRSIZE computer program will be illustrated.

References

1.	N. Aldea, Andreea Gluhoi, P. Marginean, C. Cosma, Xie Yaning, Hu Tiandou, Whongua Wu and Baozhong Dong, Investigation of supported nickel catalysts by X-ray absorbtion spectrometry and X-ray diffraction using synchrotron radiation, Spectrochim. Acta B 57, (2002) 1453 
2.	N. Aldea, C. Tiusan and B. Barz, "A new X-ray line profile approximation used for the evaluation of the global nanostructure of the nickel clusters", J.  Opt.  Adv. Mat . 6, 1 (2004)  225.