Bi 3+ , Mn 2+ co-doped CaZnGe 2 O 6 red long afterglow materials were prepared by high temperature solid state reaction method. The phosphor has broad excitation band ranging from 220 nm to 350 nm with two peaks at 255 nm and 300 nm and can give blue, green and red emission band peaking at 448 nm, 530 nm and 645 nm, respectively. Due to the emission properties of Bi 3+ ions and the Bi 3+ →Mn 2+ energy transfer, the co-doped Bi 3+ ions can not only enhance the PL luminescence of the phosphor, but also adjust the emission color. After irradiation of 300 nm ultraviolet light , the phosphors exhibits long-persistent red phosphorescence. Thermoluminescence tests demonstrate that the introduction of Bi 3+ ions can increase the trap depth and trap concentration, greatly improving the afterglow time and brightness of the CaZnGe 2 O 6 : Mn 2+ phosphor. The present work might provide reference for designing new rare earth free red long afterglow materials.
Shimeng Zhang,Zeyu He,Zhiguo Wang,Zhenggang Rao,Yunlong Hu,Chunchun Li,Longlong Shu
The diopside-structured CaZnGe 2 O 6 ceramics were synthesized using the conventional solid-state reaction method in this study, and their crystal structure, microstructural evolution, and microwave dielectric properties were systematically investigated. The XRD and Rietveld refinement analyses confirmed that CaZnGe 2 O 6 crystallizes in the monoclinic crystal system with a C 2/ c space group. The intrinsic microwave dielectric properties of the ceramics were evaluated using far-infrared spectroscopy. The ceramic structure exhibits high density and microstructural homogeneity after sintering at 1130 °C, resulting in exceptional microwave dielectric properties achieved at this optimal temperature ( ε r = 8.78 Q×f = 63,782 GHz, τ f = −66.4 ppm/°C). These findings highlight the potential application of CaZnGe 2 O 6 ceramics as low-permittivity materials suitable for microwave devices.
危险品化学品经营许可证（带存储）