Abstract:
The structure, IR absorption and luminescence spectra of the microcrystals of Lu1−xRExBO3, Lu0.99−xTbxEu0.01BO3, and Lu0.99−xYxEu0.01BO3 orthoborates (0 ⩽x⩽ 0.25) synthesized at 970∘С were studied. An increase in х leads to a sequential change of the structural state of the orthoborates. At x⩽ 0.07 – 0.09, the compounds form a solid solution with the calcite structure and microcrystal size of 8 – 20 μm. Then, they become two-phase: the vaterite phase arises along with the calcite structure. At x⩾ 0.2 – 0.25, the entire bulk of a sample has the vaterite structure. A correspondence between the structure and spectral characteristics of these compounds was established. Luminescence spectra were investigated at different wavelengths of exciting light. This allowed obtaining information on the structure of a near-surface layer and the bulk of microcrystals of the investigated samples. It is shown that the vaterite phase arises both in the bulk of large microsrystals (8 – 20 μm) and in the form of small microsrystals (1 – 2 μm).
Keywords:
luminophors for light-emitting diodes, rare-earth orthoborates, X-ray phase analysis, IR spectroscopy, luminescence spectra.
Citation:
S. Z. Shmurak, V. V. Kedrov, A. P. Kiselev, T. N. Fursova, I. I. Zver'kova, E. Yu. Postnova, “The peculiarities of the spectral characteristics of different Lu1−xRExBO3 structural modifications”, Fizika Tverdogo Tela, 63:10 (2021), 1617–1632; Phys. Solid State, 63:12 (2021), 1795–1810