Lanthanum Molybdate Nanoparticles from the Bradley Reaction: Factors Influencing Their Composition, Structure, and Functional Characteristics as Potential Matrixes for Luminescent Phosphors

[Image: see text] Interaction of lanthanum isopropoxide with molybdenum(VI) alkoxides in La/Mo ratios varying from 3:1 to 1:1 in acetophenon or allyl alcohol as solvents offers nanosized poorly crystalline products of complex composition, where the precipitation of Mo-rich ones is followed by the formation of La-rich ones with conservation of the reaction stoichiometry in total. Thermal treatment of the precipitates at temperatures over 700 °C leads to the formation of stoichiometric phases of the α- and β-La(2)Mo(2)O(9) compositions. Introduction of smaller Re(3+) cations such as Sm(3+) by doping favors stabilization of the La(2–x)RE(x)Mo(2)O(9) phase with improved crystallinity even after lower-temperature thermal treatment. The doping is successful only when the Re(3+) (Sm(3+), Eu(3+), and Tb(3+)) is introduced as an alkoxide: application of Re(3+)(acac)(3) as Re(3+) sources leads to materials free from Re(3+). The produced samples were characterized by XPD, TGA, SEM, and TEM studies as well as the luminescent properties for the Sm(3+)-doped phases.