Hydrothermal synthesis and thermal properties of a novel cubic ZrW1.80V0.20O7.90 solid solution

Tetragonal ZrW1.80V0.20O6.90(OH)2.00(H2O)2.00 hydrate was prepared using an acidic steam hydrothermal (ASH) method. Thermal dehydration followed by phase transformation of this precursor leads to successful synthesis of a novel W-site low-valent substituted cubic ZrW1.80V0.20O7.90 solid solution, the mechanism of this process is studied in detail revealing the hydrate and a metastable orthorhombic phase of V'Wsubstitution solid solution as important intermediate product. This material is found to possess thermal contraction and order-disorder phase transformation properties similar to that of the cubic ZrW2O8. -- Graphical Abstract: A novel cubic ZrW1.80V0.20O7.90 solid solution (a) was synthesized through its metastable orthorhombic phase (b) as the dehydration product of hydrate precursor ZrW1.80V0.20O6.90(OH)2.00(H2O)2.00 (c). Display Omitted Highlights: → The details of ZrW1.80V0.20O6.90(OH)2.00(H2O)2.00 dehydration process is revealed. → V5+ remaining a substitution state is crucial to the formation of c-ZrW1.80V0.20O7.90. → Synthesis of a novel aliovalent W-site substituted cubic ZrW1.80V0.20O7.90 was achieved. → Phase transition temperature and thermal contraction were determined for c-ZrW1.80V0.20O7.90.