Studies of the fractal microstructure of nanocrystalline and amorphous chromium obtained by electrodeposition

Nanocrystalline materials are of high technological and scientific interest because their internal microstructure can affect many macroscopic properties like hardness, corrosion resistance and magnetic properties. In this paper we discuss the properties of electrodeposited Cr. The nanocrystalline (n-Cr) and amorphous (am-Cr) samples were prepared by an electrochemical method. The deposited n-Cr has crystallites with grain diameters of about 30 nm. The microstructure of the obtained materials has been studied by density measurements, X-ray diffraction and small angle neutron scattering (SANS). X-ray diffraction shows completely different atomic arrangements in n-Cr and am-Cr, but the SANS results are very similar to each other. The microstructure of both n-Cr and am-Cr can be described as a surface fractal with fractal dimension of 2.24(3) and 2.22(3) for n-Cr and am-Cr, respectively.