Zeolitic imidazolate framework-8(ZIF-8),a metal-organic framework(MOF)with a non-centrosymmetric crystal structure,exhibits nonlinear optics(NLO)properties and can act as the nanoporous matrix of guest molecules.Amorp...Zeolitic imidazolate framework-8(ZIF-8),a metal-organic framework(MOF)with a non-centrosymmetric crystal structure,exhibits nonlinear optics(NLO)properties and can act as the nanoporous matrix of guest molecules.Amorphization of ZIF-8 can be achieved by pressure or high temperature.Both crystalline and amorphous states have their inherent features for optical applications.The effects of the crystalline-amorphous transition on the structural and optical properties under pressure were investigated in detail.Amorphization leads to the destruction of the ZIF-8 lattice structure,collapse of pores,and the change of spatial symmetry,which in turn alters the NLO properties of ZIF-8 and the luminescence properties of the guest Eu cations.Our results establish the structure–optical properties relationship in the amorphization process and provide new clues in designing novel MOFs optical materials.展开更多
The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized w...The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized with X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, transmittance spectroscopy and specific heat measurement. Results revealed that with proper Nd doped, Nd^（3＋） ions solid dissolved in Al_2O_3 lattice, resulting in small and uniform grain and high bonding vibration, which was beneficial to transparent and thermal properties. With 1000 ppm Nd doped, Al_2O_3 translucent ceramics showed a total transmittance of 89% and thermal conductivity of 41.7 W/m/K, indicating a potential application as substrate for effective heat dissipation and multi emitting surface in LEDs module.展开更多
基金financially supported by the National Key Research&Development Program of China(No.2017YFB0310503)National Natural Science Foundation of China(Nos.U1830125,11535010,and 52002384)the support of Pujiang Talent Plan(No.2020PJD079)。
文摘Zeolitic imidazolate framework-8(ZIF-8),a metal-organic framework(MOF)with a non-centrosymmetric crystal structure,exhibits nonlinear optics(NLO)properties and can act as the nanoporous matrix of guest molecules.Amorphization of ZIF-8 can be achieved by pressure or high temperature.Both crystalline and amorphous states have their inherent features for optical applications.The effects of the crystalline-amorphous transition on the structural and optical properties under pressure were investigated in detail.Amorphization leads to the destruction of the ZIF-8 lattice structure,collapse of pores,and the change of spatial symmetry,which in turn alters the NLO properties of ZIF-8 and the luminescence properties of the guest Eu cations.Our results establish the structure–optical properties relationship in the amorphization process and provide new clues in designing novel MOFs optical materials.
基金supported by the project of Natural Science Foundation of Zhejiang Province(LY15F050005 and LZ14B010001)
文摘The transparent and thermal developments of high-purity Al_2O_3 doped with different levels of Nd_2O_3 were investigated. Dopant levels ranged from 500–1500 ppm（Nd/Al atomic ratio）. The samples were characterized with X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, transmittance spectroscopy and specific heat measurement. Results revealed that with proper Nd doped, Nd^（3＋） ions solid dissolved in Al_2O_3 lattice, resulting in small and uniform grain and high bonding vibration, which was beneficial to transparent and thermal properties. With 1000 ppm Nd doped, Al_2O_3 translucent ceramics showed a total transmittance of 89% and thermal conductivity of 41.7 W/m/K, indicating a potential application as substrate for effective heat dissipation and multi emitting surface in LEDs module.
