Facile combustion synthesis of TbFeO$_{3}$ nanocrystals with hexagonal and orthorhombic structure

In this research, the formation process of nanocrystalline terbium orthoferrite (TbFeO$_{3}$) obtained via a solution combustion technique was studied using powder X-ray diffractometry, scanning electron microscopy, $^{57}$Fe Mössbauer spectroscopy, N$_{2}$ adsorption analysis, and FTIR spectroscopy. It was shown that glycine-nitrate combustion method permits one to obtain TbFeO$_{3}$ of three different modifications: orthorhombic o-TbFeO$_{3}$ (Pbnm), hexagonal h-TbFeO$_{3}$ (P6$_{3}$/mmc) and amorphous am-TbFeO$_{3}$. It was found that the average crystallite sizes of orthorhombic and hexagonal TbFeO$_{3}$ were $29\pm3$ and $15\pm2$ nm, respectively. The formation mechanism of different structural forms of terbium orthoferrite was investigated on the basis of nanopowders morphology, specific surface areas, average pore sizes, and crystallite sizes.