RT info:eu-repo/semantics/article
T1 Solid-State synthesis and phase transitions in the RE2(MoO4)3 family monitored by thermodiffraction
A1 Torres Betancort, Manuel Eulalio
A1 Silva, Ivan da
A1 Gil de Cos, Gerardo
A1 González-Silgo, Cristina
A1 López-Solano, Javier
A1 Mujica, Andrés
A1 Ramírez-Rodríguez, Nivaria R.
A1 Torres, Manuel E.
AB Solid-state synthesis and phase transitions of RE2(MoO4)3 (RE ≡ Nd, Sm, Eu, and Gd) samples have been monitoredby X-ray thermodiffraction with synchrotron radiation. The experiment was divided in two stages. In the first heating, different nonstoichiometric molybdates (Eu4Mo7O27, Eu2Mo4O15, and Pr2Mo4O15 structure types) emerged from the RE2O3 and MoO3 oxidesbefore the expected phases (with α-Eu2(WO4)3 and La2(MoO4)3 structure types and the β-Gd2(MoO4)3 phase). The formation andcoexistence of intermediate phases have been explained by common structural motifs with unit cell volumes per atom among thosewith the formula RE2(MoO4)3. Subsequent heating−cooling cycles showed the occurrence of the reversible and reconstructive α[La2(MoO4)3] ↔ β phase transition, including the less common transition β → α [La2(MoO4)3] obtained by heating the β′-Gd2(MoO4)3 phase from room temperature and clarifying much of the controversy in the literature. The transition mechanisms werestudied by proposing a common supercell and comparing the RE and vacancy ordering within similar layers of MoO42− tetrahedra.The possible formation of stacking faults in Nd2(MoO4)3 was explained as a mixture of modulated scheelite phases. This researchsupports the importance of a directed and rational synthesis analyzing the intermediate products and their phase transitions for theenrichment of materials with new or improved properties.
SN 1528-7505
YR 2023
FD 2023
LK http://riull.ull.es/xmlui/handle/915/35488
UL http://riull.ull.es/xmlui/handle/915/35488
LA en
DS Repositorio institucional de la Universidad de La Laguna
RD 27-nov-2024