Synthesis of ZrMo2O8 polymorphs by a melt quenching method and mechanochemical activation

Abstract This study presents two new approaches: the melt quenching method (up–down) and mechanochemical activation (down–up) for the preparation of single ZrMo 2 O 8 polymorphs. A stoichiometric mixture of ZrO 2 and MoO 3 in a 1:2 molar ratio was subjected to melt quenching with different cooling rates and intense mechanical treatment in air using a planetary ball mill (Fritsch No. 7). The phases obtained and their transformations were monitored by X-ray diffraction (XRD), infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Trigonal (α) ZrMo 2 O 8 is the first phase obtained by the melt quenching method. The same phase was prepared by mechanochemically assisted solid state synthesis. The additional heat-treatment led to phase transition to monoclinic (β) ZrMo 2 O 8 . It was established that these methods allowed a shorter synthesis time of ZrMo 2 O 8 polymorphs as compared to the traditional solid state synthesis.