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Single-component-tunable blue-to green-light-emitting phosphors Ba3Sr4(BO3)3F5: Ce3+, Tb3+, Na+ (BSBF: Ce3+, Tb3+, Na+) promising for near-UV-pumped light-emitting diodes (LEDs) were synthesized via high-temperature solid-state reactions, and their photoluminescence properties were systematically investigated. Upon the excitation of 360 nm, the BSBF: Ce3+, Tb3+, Na+ phosphors exhibited a broad blue emission band at 422 nm and a series of sharp emission lines at 490, 544, 585, and 623 nm, which originated from the 4f 05d 1–4f 1 transition of Ce3+ ions, and 5 D 4–7 F J (J = 6, 5, 4, 3) transitions of Tb3+ ions, respectively. Through the resonance-type energy transfer, the varied emitted colors from blue through cyan and eventually to green were achieved by properly tuning the relative dopant composition of Ce3+/Tb3+. Moreover, the energy transfer from Ce3+ to Tb3+ in BSBF host matrix was demonstrated via the dipole–dipole interaction mechanism. Additionally, the critical distances ( $$ R_{\text{C}} $$ ) calculated by quenching concentration and spectral overlap method in such system were 2.166 and 1.940 nm, and the activation energy for thermal quenching (ΔE) was determined to be 0.117 eV. These results indicate that the developed color-tunable phosphors BSBF: Ce3+, Tb3+, Na+ are competitive as the promising single-component phosphor-converted materials for near-UV-pumped LEDs.

Electroplastic rolling (EPR) of Bi-2223/Ag superconducting wires was performed, where pulse currents were applied during rolling to introduce an electroplastic effect. It was found that the rolling force decreased significantly compared with the traditional rolling process. Furthermore, EPR favorably minimized the sausage effect. It is revealed that the electroplastic effect can facilitate the mechanical deformation of Bi-2223/Ag composites. Segments of the Bi-2223/Ag tapes were heat treated at 830 °C for different time periods. The phase assemblies of these samples suggest that current pulses contribute to faster transformation kinetics from the Bi-2212 phase to the Bi-2223 phase. In addition, a preliminary improvement of 28% of critical current density has been achieved in a fully processed tape with EPR.

Double-perovskite Sr2Ca1−2x Eu x Na x MoO6 red-emitting phosphors were prepared by the citric acid-assisted sol–gel method, and their luminescence properties were investigated as a function of sintering temperature and Eu3+-doping concentration. B-site substituted Sr2Ca0.8Eu0.1Na0.1MoO6 phosphor, in which Na+ ions act as charge compensators, was selected to study the thermal behavior, phase structure, microstructure, and photoluminescence property under different sintering temperatures. The photoluminescence studies on Sr2Ca1−2x Eu x Na x MoO6 (x = 0.02, 0.05, 0.10, 0.15, 0.2) show that a dominant red emission line at around 594 nm, which is due to the Eu3+ magnetic dipole transition of 5D0–7F1, is observed under different Eu3+ excitations (396 and 412 nm). Further, Eu3+ dopant content dependent emission spectra investigations of Sr2Ca1−2x Eu x Na x MoO6 phosphors indicates that, when the Eu3+ concentrations x = 0.05, there are minimum differences between the emission intensity of 5D0–7F1 transition at 594 nm and that of 5D0–7F2 transition at 615 nm. With increasing Eu3+ concentration, the variation of the emission intensities between the two transitions keep nearly invariable and Sr2Ca0.8Eu0.1Na0.1MoO6 phosphor has the strongest red emission in this series.