Tuesday, September 6, 2016

Growth of single crystals of BaFe12O19 by solid state crystal growth

Highlights

•Single crystals of BaFe12O19 are grown by solid state crystal growth.

•A single crystal up to~130μm thick (c-axis direction) grows on the seed crystal.

•The single crystal and surrounding ceramic matrix have similar composition.
•Micro-Raman scattering shows the single crystal has the BaFe12O19 structure.

Single crystals of BaFe12O19 are grown for the first time by solid state crystal growth. Seed crystals of BaFe12O19 are buried in BaFe12O19+1 wt% BaCO3 powder, which are then pressed into pellets containing 
the seed crystals. During sintering, single crystals of BaFe12O19 up to ~130μm thick in the c-axis direction grow on the seed crystals by consuming grains from the surrounding polycrystalline matrix. Scanning electron microscopy-energy dispersive spectroscopy analysis shows that the single crystal and the surrounding polycrystalline matrix have the same chemical composition. Micro-Raman scattering shows the single crystal to have the BaFe12O19 structure. The optimum growth temperature is found to be 1200 °C. The single crystal growth behavior is explained using the mixed control theory of grain growth.
 
Keywords:  BaFe12O19;  Single crystal;  Scanning electron microscopy;  Raman scattering;  Grain growth

Source: Sciencedirect