Search

A series of Sm3 +-doped 0. 96Na0 .5Bi0.5TiO3-0.04CaTiO3 (NBT-0. 04CT:xSm3+, 0. 002 ≤x ≤ 0. 020) lead-free piezoelectric ceramics were prepared by a conventional solid-state reaction method. The phase structures of the samples were characterized by X-ray diffractometry, and all the samples show a single perovskite structure. The photoluminescence properties of the samples were measured by fluorescence spectrophotometer, and the samples show the strongest excitation peak at 479 nm, which matches well with the blue LED chip used in the white LED synthesis. The dominant emission peak is located at 597 nm (4G5/2→ 6 H7/9), presenting strong orange-red luminescence. NBT-0. 04CT:0. 010Sm3+ ceramics shows optimal luminescence performances among the Sm3 +-doped NBT-0. 04CT ceramics, and superior thermal stability of its luminous properties is achieved in the temperature range from 278 K to 473 K. The results indicate that NBT-0. 04CTxSm3 + ceramics have promising applications in white LED. [ABSTRACT FROM AUTHOR]

[Display omitted] • A moderate amount of Dy3+ doping can enhance the ferroelectricity of the NBT host. • The NBT: x Dy3+ specimens exhibit intense prominent orange-yellow emission with optimal performance for x = 0.012. • The NBT: 0.012Dy3+ ceramic could be applied to optical temperature sensing. A series of Dy3+ doped Na 0.5 Bi 0.5 TiO 3 (NBT: x Dy3+, x = 0.003–0.018) lead-free ferroelectric ceramics were successfully prepared by a solid-state reaction method. The Dy3+ ions composition dependent photoluminescence properties were systematically studied. All the samples display intense characteristic emission of Dy3+ under an excitation wavelength of 454 nm, which are attributed to the transitions of 4F 9/2 → 6H J /2 (J = 13, 11 and 9). All the samples show strong orange-yellow emission, which could be applied to warm white light hopefully. When the content of Dy3+ is equal to 0.012, the ceramic has the optimal luminous performance. Remarkable thermal quenching of the luminous intensity ceramic occurs as the temperature is higher than initial temperature 293 K. Furthermore, Dy3+ activated photoluminescence performance combined with the presence of ferroelectricity in the NBT host can be applied to developing non-contact optical temperature sensitive materials and other future novel optoelectronic devices. [ABSTRACT FROM AUTHOR]

A series of Sm3+ doped 0.92(Na 0.5 Bi 0.5)TiO 3 -0.08(Ba 0.90 Ca 0.10)(Ti 0.92 Sn 0.08)O 3 (NBT-8BCTS: x Sm3+, x = 0–0.025) lead-free piezoelectric ceramics are fabricated via a conventional solid-state reaction method, and their phase structure, photoluminescence properties and temperature dependent of luminescence spectra are studied in detail. The emission spectra with dominant orange-red emission consist of four emission peaks at 542 nm, 598 nm, 644 nm and 709 nm, which are ascribed to the 4G 5/2 → 6H J/2 (J = 5, 7, 9, 11) transition of Sm3+ ions, respectively. Furthermore, the optical temperature sensing properties of the NBT-8BCTS: 0.01Sm3+ ceramic in the temperature range between 313 K and 533 K are analyzed with a maximum relative sensitivity 1.29%K−1 at T = 463 K. Besides, the phosphors exhibit excellent stable temperature sensing performance under repeated heat-cooling cycles. These results suggest that the Sm3+ doped NBT-8BCTS ceramics may have potential applications in multifunctional sensing devices by integrating its optical temperature sensing and intrinsic ferroelectric property. [Display omitted] • Ferroelectricity and photoluminescence emissions coexist in NBT-BCTS: x Sm3+. • A maximum relative sensitivity of 1.29% K−1 at 463 K is obtained. • Sm doped NBT-BCTS ceramics have potential for developing multifunctional optical-electric devices. [ABSTRACT FROM AUTHOR]