Goal of the present research was to apply a solid state reaction route to fabricate bismuth layer-structured multiferroic ceramics described with the formula Bi5FeTi3O15 and reveal the influence of processing conditions on its crystal structure and phase composition. Simple oxide powders Bi2O3, TiO2 and Fe2O3 were used to fabricate Aurivillius-type bismuth layer-structured ferroelectrics. Pressureless sintering in ambient air was employed and the sintering temperature was TS = 900°C, TS = 1000°C and TS = 1040°C. The phase composition as well as crystal structure of ceramics sintered at various processing conditions was examined with powder X-ray diffraction method at room temperature. The Rietveld refinement method was applied for analysis of X-ray diffraction data. It was found that ceramics adopted orthorhombic structure Cmc21. The unit cell parameters of bismuth layer-structured multiferroic ceramics increased slightly with an increase in sintering temperature.

A description of the status of the art of experimental and theoretical investigations of local crystalline structures of tetrahedron ordered ternary and quaternary semiconducting alloys is presented. Experimental EXAFS data and FTIR analysis are summarized and analyzed using both the Rigid Network Cations theoretical model and the Strained-tetrahedra model. Internal preferences of ion pairs in ternary and quaternary alloys are discussed. Several ternary systems of different structures show ideal quasi-canonical Bernoulli distributions, while others are characterized by extreme preferences in which one, several or even all configurations are depressed or even lacking. The results demonstrate that the validity of the Bernoulli distribution is limited and not fulfilled in many systems. This article is an expanded version of the scientific reports presented at the International Conference on Semiconductor Nanostructures for Optoelectronics and Biosensors 2016 ICSeNOB2016, May 22–25, 2016, Rzeszow, Poland.