Amorphous–crystalline transition studied in hydrated MoO3

✍ Scribed by M.A. Camacho-López; E. Haro-Poniatowski; L. Lartundo-Rojas; J. Livage; C.M. Julien

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 713 KB
• Volume: 135
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2006.08.041

✦ Synopsis

In this work we study the thermal behavior of hydrated MoO 3 synthesized via acidification of sodium molybdate. MoO 3 •nH 2 O (n = 1.4) amorphous compound was heated in air at increasing temperatures in order to obtain the crystalline MoO 3 phase. We have studied the structural changes as a function of annealing temperature by Raman spectroscopy. A statistical study to determine the average size of the crystallites at each annealing step has been realized by scanning electron microscopy. Results show that the hydrated MoO 3 •1.4H 2 O glass transforms in an amorphous MoO 3 •0.7H 2 O phase prior to its crystallization, while the sample heated at 500 • C crystallizes into the orthorhombic ␣-MoO 3 phase with micro-crystallites having an average size of 6.8 m.