CASPIAN JOURNAL
MANAGEMENT AND HIGH TECHNOLOGIES
 |
Read | Galiyarova Nina M., Strelyaeva Aleksandra B. // Caspian journal : management and high technologies. — 2012. — №2. — pp. 114-120. |
Galiyarova Nina M. - Sc.D. (Physics and Mathematics), Professor, Volgograd State Architectural and Building University, 400074, Russia, Volgograd, 1, Akademicheskaya st., galiyarova@mail.ru.
Strelyaeva Aleksandra B. - assistant, Volgograd State Architectural and Building University, 400074, Russia, Volgograd, 1, Akademicheskaya st., beyab@mail.ru.
The microstructure of PZTNB-1 piezoceramics (the lead-zirconate-titanate solid solutions doped with sodium and bismuth) has been studied in the morphotropic phase boundary region of tetragonal and rhombohedral phases. The measurements have been provided by optic and atomic-force microscopy (AFM) methods. By optic methods the distributions of grain and pore sizes were studied and their shape parameters evaluated. The revealed correlation between squires and perimeters witness about statistic similarity of the microstructure and allowed to determine the fractal dimensionalities of elements. There are determined not only local but also the global fractal dimensionality of grain boundaries, equal 1,58 a 0,02. The received values considerably exceed topological dimension of a line due to fracture of boundaries. Roughness of the surface of grains and the bottom of pores, fracture of rugged boundaries, domain structure of grains were visualized by AFM method. The details of relief of pore’s bottom, the depth of grain interfaces are revealed. In particular, the depth of a pore is about 400 nanometers and width is 10 microns. The bottom of a pore isn’t flat, it contains hills of 150–200 nm in height. The depth of grain interfaces is about 500 nm. Average width of domains is about 100 nm. It is noticed that local fractal dimension and the parameters, characterizing the form and asymmetry of grains, reach a maximum in the morphotropic phase boundary region, correlating with macroscopic properties.
Key words: ferroelectrics,piezoceramics,morphotropic phase boundary,lead zirconate-titanate (PZT),microstructure,fractals,grains,domains,fractal dimensionalities