The effects of pH and excess Al3+ content on the microstructure and phase evolution of YAG polycrystals. Issue 15 (15th October 2017)

• Record Type: Journal Article
• Authors: Rahmani, Mahsa; Mirzaee, Omid; Tajally, Mohammad; Loghman-Estarki, Mohammad Reza
• Is Part Of: Ceramics international. Volume 43:Issue 15(2017)
• Page Start: 12563
• Page End: 12571
• Publication Date: 2017-10-15
• Subjects: YAG -- Normal co-precipitation -- pH -- Y/Al ratio; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.06.131
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: YAG precursors were synthesized via a surfactant-free co-precipitation method using ammonium hydrogen carbonate as precipitant. The effect of final pH on Y/Al molar ratio was investigated. Moreover, the effects of excess aluminum ion content on the phase evolution and characteristics of YAG powders synthesized at pH value of 8 were explored. The chemical composition of the precursor, the phase transformation process and the characterization of the products were investigated by means of ICP, XRD, FTIR, TG-DTA, BET, FESEM, TEM and EDX analysis. The results showed that relatively high Y/Al ratio reduced the kinetics of YAG transformation and decreased homogeneity of the precursor while low Y/Al ratio did not alter the process features. Pure YAG nanopowders with particles mean diameter of 45 nm were obtained by calcination at 1000 °C for 2 h, with the addition of 15% mole of the excess aluminum source at pH value of 8.