Effect of magnesium source on the fabrication of kotoite Mg ₃ B ₂ O ₆ ceramic

Abstract The effect of magnesium source on the fabrication of kotoite, Mg ₃ B ₂ O ₆ , ceramic has been investigated by high temperature solid‐state reaction route based on the calcination of different magnesium sources, containing magnesium oxide, magnesium carbonate, magnesium sulfate, and magnesium nitrate with boric acid. The X‐ray powder diffraction results showed that single‐phase kotoite, Mg ₃ B ₂ O ₆ , was synthesized using Mg NO ₃ .6H ₂ O and 5 wt.% excess of H ₃ BO ₃ powders as starting materials at 900°C for 48 hours. Mg ₃ B ₂ O ₆ obtained, is well crystallized, in orhorhombic crystal structure with lattice parameters of a = 5.399(9), b = 8.424(6), and c = 4.506(5) Å. Jana2006 refinement of this product shows excellent fit of the experimental data with software data, GOF = 1.33. The crystallite size of the product was calculated as 40.50 nm using Debye‐Scherrer's equation. The existence of BO ₃ triangles were detected by FTIR measurements of Mg ₃ B ₂ O ₆ . The thermal properties were studied in the temperature range of 20°C to 1400°C by TG / DTA . The results showed that thermal stability of Mg ₃ B ₂ O ₆ is detected about 1380°C. Scanning electron microscopy was employed for observation of microstructure. The microstucture of obtained ceramic samples strongly depended on the magnesium source on the fabrication of Mg ₃ B ₂ O ₆ ceramic.