Model of Fractal Particles of Hydrated Zirconium Dioxide, Based on Small-Angle Neutron Scattering Data

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques Vol. 13; no. 5; pp. 908 - 913
• Main Authors: Azarova, L. A., Kopitsa, G. P., Iashina, E. G., Garamus, V. M., Grigoriev, S. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2019; Springer Nature B.V
• Subjects: Annealing; Chemistry and Materials Science; Crystallization; Fractal models; Fractal transforms; Heat treatment; Materials Science; Nanoparticles; Neutron scattering; Neutrons; Surfaces and Interfaces; Thin Films; Zirconium; Zirconium dioxide; zirconium dioxide; small-angle neutron scattering; surface fractal; mass fractal
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S1027451019050215

The parameters of the mesostructure of amorphous zirconium dioxide and their evolution at different stages of heat treatment are determined by small-angle neutron scattering. Particles of amorphous zirconium dioxide, which form mass fractals with the dimension D v = 2.21, are rearranged into surface fractals with a surface dimension of D s = 2.52 upon annealing at a temperature of 400°C or higher. In the resulting system, a shell with a fractal structure is formed over a dense core (a cluster of nanoparticles of zirconium dioxide with a constant density). Transformation of the fractal system from a mass fractal into a surface one is characterized by the appearance of a core, and its growth is due to the crystallization of hydrated zirconia particles at high temperatures. A model for the formation of a fractal particle, implying the existence of a core–shell surface fractal system, is proposed. The characteristic radius of ZrO 2 nanoparticles increases from 14 to 200 Å with an increase in the annealing temperature from 400 to 600°C.