Akademik Veri Yönetim Sistemi
Journal of Materials Science: Materials in Electronics, cilt.36, sa.1, 2025 (SCI-Expanded, Scopus)
The hypersensitive transitions are those in which oscillator strengths change sensitively in response to small changes in the surrounding environment. The study makes a structural, morphological, and spectral comparison of the electric dipole transitions of BaTa2O6:RE3+, B3+ (RE = Sm,Dy) phosphor series with the hypersensitive electric dipole transition of BaTa2O6:Eu3+, B3+. The structural, morphological and optical properties was investigated using BaTa2O6:xSm3+, yB3+ (x = 5 mol%, y = 0–100 mol%) and BaTa2O6:xDy3+, yB3+ (x = 10 mol%, y = 0–100 mol%) ceramics fabricated by the solid-state reaction. X-ray diffraction results for all samples revealed that the single-phase structure was maintained up to 100 mol% B3+, along with an enhancement in crystallinity. Scanning electron microscope (SEM) micrographs of the ceramic samples showed that the presence of boron as a flux agent prometed the growth of grains and resulted in an elongated grain morphology. The direct band gap energies (Eg) determined from UV–Vis reflectance spectra decreased with increasing boron amount. PL emissions of BaTa2O6:RE3+, B3+ (RE = Sm, Dy) phosphors increased up to 100 mol% B3+ concentration, correlating with the increase in grain size and improvement in crystallinity. Both phosphor series showed similar structural and morphological properties with the reported results of BaTa2O6:Eu3+, B3+ phosphors, however, differences were observed in their spectral properties. In the comparison of the asymmetry ratio of three series, there was a slight change in the 4G5/2 → 6H9/2/4G5/2 → 6H5/2 and 4F9/2 → 6H13/2/4F9/2 → 6H15/2 ratios that are related to the Sm3+ and Dy3+ asymmetry, respectively, whereas the change of asymmetry ratio (5D0 → 7F2/5D0 → 7F1) was evident in Eu3+ ion. In both series with bi-exponential decay curves, the observed lifetimes decreased depending on the B3+ concentration and slight changes in short and long lifetimes occurred. In the CIE diagram, the chromatic coordinates (x, y) of the phosphors were located in the red and yellow regions for Sm3+ and Dy3+, respectively.