Novel kinds of down/up-conversion luminescent rare earth doped fluoride BaMgF4: RE3+ microcrystals

Graphical abstract: We achieve the liquid phase chemical synthesis of rare earth fluoride system BaMgF4: RE3+ microphosphors, which realize down/up-conversion luminescence. - Highlights: • Doped BaMgF4 microphosphors are firstly prepared by hydrothermal process. • Doped BaMgF4 nanosheets are firstly prepared by high temperature solution reaction. • The down-conversion luminescence is realized in the rare earth doped BaMgF4. • The upconversion luminescence is realized in the rare earth doped BaMgF4. - Abstract: In this paper, we realize the liquid-phase chemical synthesis of high-quality orthorhombic polycrystalline BaMgF4: RE3+ (RE = Eu, Tb, Sm, Dy, Yb–Er/Tm) compounds with hydrothermal and high-temperature solution methods, respectively. The products from hydrothermal technology show the micrometer size while the products from hydrothermal technology present nanosheet morphology. The rare earth ions doped BaMgF4 from hydrothermal synthesis are discussed in details, which can realize the downconversion luminescence for doped Eu3+ or Tb3+ and upconversion luminescence for Yb3+/Er3+ (Tm3+), respectively. To our knowledge, the hydrothermal or high temperature solution synthesis and photoluminescence (Eu3+, Tb3+ or Yb3+/Er3+(Tm3+)) of these fluoride systems are firstly reported