Dy^(3+) and Lu^(3+) co-doped CaLaGa_(3)O_(7) phosphors were prepared via high-temperature solid-phase reaction.The electronic structures of LuxCaLa_(0.98-x)Ga_(3)O_(7) were investigated by the first-principles calcula...Dy^(3+) and Lu^(3+) co-doped CaLaGa_(3)O_(7) phosphors were prepared via high-temperature solid-phase reaction.The electronic structures of LuxCaLa_(0.98-x)Ga_(3)O_(7) were investigated by the first-principles calculations.The influence of Lu^(3+) on yellow light emission was studied using X-ray diffraction(XRD)and photoluminescence(PL) measurements.The XRD results indicate that compared to Dy^(3+):CaLaGa_(3)O_(7),the cell parameters of Dy^(3+):LuCaLaGa_(3)O_(7) tend to decrease,which is due to the smaller radius of Lu^(3+).When pumped by blue GaN laser diode(LD),the emission peaks of phosphors with different Lu^(3+)doping concentrations in the visible region are similar,with the strongest peak at 574 nm in the yellow light region,which is sensitive to human eyes.The optimal doping concentration of Lu^(3+) is confirmed to be1 at%,when all emission spectra and measured fluorescence lifetimes are taken into account.Moreover,the optimal phosphor composition Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7)(x=0.01) has an internal quantum efficiency(IQE) of 46.94% and an external quantum efficiency(EQE) of 15.19%.Most notably,the prepared phosphor demonstrates excellent thermal stability and a high activation energy(0.203 eV).In addition,the International Illumination Commission color coordinates of the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7) phosphors are in the yellow light area.The above analysis indicates that the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7)(x=0.001)phosphor has promising application prospects in yellow light-emitting devices.展开更多
用铁鳞作为主料,优化设计了产品的主配方,结合铁鳞的两级氧化处理技术、助溶剂辅料A的添加技术,用常规陶瓷工艺制备了Ca La永磁铁氧体。用振动样品磁强计、永磁铁氧体测量仪、浮力法、惠斯顿电桥法、产品压力试验机对产品相关磁特性进...用铁鳞作为主料,优化设计了产品的主配方,结合铁鳞的两级氧化处理技术、助溶剂辅料A的添加技术,用常规陶瓷工艺制备了Ca La永磁铁氧体。用振动样品磁强计、永磁铁氧体测量仪、浮力法、惠斯顿电桥法、产品压力试验机对产品相关磁特性进行了检测。与传统离子取代技术相比,所获磁体的各参数均能得到了明显的改善,磁体的典型参数为:Br=0.453 T,Hcb=322.5 k A·m-1,Hcj=415.4 k A·m-1。展开更多
基金supported by the Shandong Provincial Natural Science Foundation (ZR2020QE034,ZR2021QF081)National Natural Science Foundation of China (11974304)Anhui Provincial Natural Science Foundation(2008085QA45,2008085QA49)。
文摘Dy^(3+) and Lu^(3+) co-doped CaLaGa_(3)O_(7) phosphors were prepared via high-temperature solid-phase reaction.The electronic structures of LuxCaLa_(0.98-x)Ga_(3)O_(7) were investigated by the first-principles calculations.The influence of Lu^(3+) on yellow light emission was studied using X-ray diffraction(XRD)and photoluminescence(PL) measurements.The XRD results indicate that compared to Dy^(3+):CaLaGa_(3)O_(7),the cell parameters of Dy^(3+):LuCaLaGa_(3)O_(7) tend to decrease,which is due to the smaller radius of Lu^(3+).When pumped by blue GaN laser diode(LD),the emission peaks of phosphors with different Lu^(3+)doping concentrations in the visible region are similar,with the strongest peak at 574 nm in the yellow light region,which is sensitive to human eyes.The optimal doping concentration of Lu^(3+) is confirmed to be1 at%,when all emission spectra and measured fluorescence lifetimes are taken into account.Moreover,the optimal phosphor composition Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7)(x=0.01) has an internal quantum efficiency(IQE) of 46.94% and an external quantum efficiency(EQE) of 15.19%.Most notably,the prepared phosphor demonstrates excellent thermal stability and a high activation energy(0.203 eV).In addition,the International Illumination Commission color coordinates of the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7) phosphors are in the yellow light area.The above analysis indicates that the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7)(x=0.001)phosphor has promising application prospects in yellow light-emitting devices.
文摘用铁鳞作为主料,优化设计了产品的主配方,结合铁鳞的两级氧化处理技术、助溶剂辅料A的添加技术,用常规陶瓷工艺制备了Ca La永磁铁氧体。用振动样品磁强计、永磁铁氧体测量仪、浮力法、惠斯顿电桥法、产品压力试验机对产品相关磁特性进行了检测。与传统离子取代技术相比,所获磁体的各参数均能得到了明显的改善,磁体的典型参数为:Br=0.453 T,Hcb=322.5 k A·m-1,Hcj=415.4 k A·m-1。
