Wet-chemical synthesis of magnesium niobate nanoparticles powders

• Published in: Ceramics international 2007-01, Vol.33 (7), p.1205-1209
• Main Authors: Santos, L.P.S., Camargo, E.R., Fabbro, M.T., Longo, E., Leite, E.R.
• Format: Article
• Language: English
• Subjects: Columbite; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; formula omitted; FT-Raman; Low temperature synthesis; Magnesium niobate; Materials science; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Physics
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2006.04.006

Nanosized and highly reactive magnesium niobate ( MgNb 2 O 6 ) powders were successfully synthesized by a new wet-chemical method by means of the dissolution of Nb 2 O 5 ⋅ 5 H 2 O and in a solution of oxalic acid followed by the addition of stoichiometric amounts of magnesium carbonate. The Nb–Mg–oxalic acid solution was evaporated resulting in a dry and amorphous powder that was calcined in the temperature range from 200 to 900 °C for 2 h. The crystallization process from the amorphous state to the crystalline MgNb 2 O 6 was followed by thermal analysis. The calcined powders characterized by FT-Raman spectroscopy, X-ray diffraction (XRD) and their morphology examined by high resolution scanning electron microscopy (HR-SEM). Pure MgNb 2 O 6 , free from the second phases and obtained at 800 °C was confirmed by a combined analysis using XRD and FT-Raman. The average diameter of the particles was calculated from the HR-SEM image as 70 nm approximately. This technique allows a better mixing of the constituent elements and thus a better reactivity of the mixture to obtain pre-reaction products with high purity at lower temperatures and reducing cost. It can offer a great advantage in the PMN-PT formation with respect to the solid-state synthesis.