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Lanthanide doped Ba 1-x Sr x TiO 3 (x = 0–1) solid-solution phosphors were successfully prepared by a conventional solid-state reaction. Using Eu 3+ dopants as the structural probe, the variation of 5 D 0 → 7 F 2 / 5 D 0 → 7 F 1 emission intensity ratio with increase of Eu 3+ content and the excitation-wavelength-dependent luminescence in the Ba 1-x Sr x TiO 3 sample were demonstrated to be originated from the different emission behaviors of Eu 3+ in Ba 2+ /Sr 2+ site and Ti 4+ site. Furthermore, upconversion luminescence for the Yb 3+ /Er 3+ co-doped Ba 1-x Sr x TiO 3 samples were investigated, and it was found that the emission intensity of Yb 3+ /Er 3+ : Ba 0.5 Sr 0.5 TiO 3 phosphor was about 5 and 2 times as high as those of Yb 3+ /Er 3+ : BaTiO 3 and Yb 3+ /Er 3+ : SrTiO 3 ones. Using the investigated Yb 3+ /Er 3+ : Ba 0.5 Sr 0.5 TiO 3 solid-solution as the optical thermometric medium, the temperature sensitivity was determined to be 0.76% K −1 at the temperature of 610 K based on the temperature-dependent fluorescence intensity ratio of the thermally coupled 2 H 11/2 and 4 S 3/2 emitting-states of Er 3+ . [ABSTRACT FROM AUTHOR]

Sb–Te alloy is widely considered as one of the important materials for phase change memory (PCM) with fast operation speed. However, the poor amorphous phase stability limits its wide application. In this work, silicon carbide (SiC) doped Sb 2 Te (Sb 2 Te-SiC) nanomaterial was proposed to improve the thermal stability of Sb 2 Te. It was found that the crystallization temperature of Sb 2 Te was remarkably improved from 149 °C to 251 °C. Accordingly, the temperature for 10-year data retention increases from 56.5 °C to 156.4 °C. X-ray diffraction and transmission electron microscope results indicate that the grain size of Sb 2 Te-SiC film was largely reduced with SiC doping. Besides, experimental results show the Sb 2 Te-SiC nanomaterial is very uniform and no phase separation was observed even after 300 °C annealing. Furthermore, the Sb 2 Te-SiC nanomaterial based PCM cells show fast operation speed of 7 ns and good endurance ability of 2.1 × 10 4 cycles. [ABSTRACT FROM AUTHOR]

Highlights: [•] We have synthesized the layered LiNi0.5Mn0.5O2−xF x (0⩽ x ⩽0.04) by hydroxide co-precipitation method. [•] The structure, morphology and electrochemical performance of LiNi0.5Mn0.5O2 are influenced by F doping effect. [•] The cations mixing of pure LiNi0.5Mn0.5O2 decreases and Li+ diffusion coefficient increases with doping F. [•] The reversible capacity of LiNi0.5Mn0.5O1.96F0.04 is 155.0mAhg−1 after 50 cycles at 0.2 C, 0.5 C and 1.0 C ratios between 2.8 and 4.6V. [ABSTRACT FROM AUTHOR]