Birefringent crystals,which can modulate the polarization of light,are particularly important in optical communication and the laser industry.Here we report the synthesis,structures,optical properties,and theoretical ...Birefringent crystals,which can modulate the polarization of light,are particularly important in optical communication and the laser industry.Here we report the synthesis,structures,optical properties,and theoretical analyses of four rare-earth borates containing BO_(3) groups,i.e.LiRb_(2)YB_(2)O_(6),CaRbYB_(2)O_(6),and Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs).Their structures are not all typical BO_(3) group distributions with large birefringence values,e.g.,being parallel with each other’s distribution or being a regular polygon distribution with a specific form that is parallel with an optical axis.However,their birefringence values exhibit an obvious increase from LiRb_(2)YB_(2)O_(6)(0.038@532 nm)to Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs)(0.103@532 nm).The origin of this birefringence increase was studied by structural analysis and theoretical calculation.First-principles calculations and structure comparisons indicate that the non-symmetry localization of electron density of the Y–O polyhedra has an important contribution to the large birefringence of Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs).展开更多
Conventional methods for quantifying thermoelectric anisotropy rely on precisely aligned crystals,which are time-consuming and error-prone.To address this,we propose a tensor inversion method integrating transport mea...Conventional methods for quantifying thermoelectric anisotropy rely on precisely aligned crystals,which are time-consuming and error-prone.To address this,we propose a tensor inversion method integrating transport measurements with EBSD-derived Euler angles to determine the intrinsic tensors of as-grown bismuth crystals.This method reconstructs the full second-rank thermoelectric tensors—including electrical resistivity,thermal conductivity,and the Seebeck coefficient—by transforming transport data between the sample coordinate system and the crystal coordinate system.The inverted tensor components of pure bismuth show excellent agreement with reported principal-axis values,validating the accuracy of this method.Moreover,the reversibility of the tensor inversion approach allows for complete visualization of the directional dependence of the thermoelectric figure of merit(zT),revealing its full angular and crystallographic orientation distribution for the first time.This bidirectional framework not only provides a convenient pathway for the reconstruction of intrinsic transport tensors but also enables the prediction of orientation-dependent properties,thereby offering a robust tool for analyzing anisotropic transport behavior and guiding the optimization of thermoelectric performance.展开更多
Y zeolite is presently used as an important active component in oil refining catalysts.The efficient synthesis of NaY zeolite still faces many huge challenges.Herein,a novel method for the rapid synthesis of nano-plat...Y zeolite is presently used as an important active component in oil refining catalysts.The efficient synthesis of NaY zeolite still faces many huge challenges.Herein,a novel method for the rapid synthesis of nano-plate-like small crystal-sized NaY zeolite through an artificial-fish-reef-breeding negative crystal strategy is reported.It was discovered that cationic polyacrylamide(CPAM)could act as an artificial fish-reef to breed negative crystals,which promoted NaY zeolite nucleation and accelerated the crystallization of NaY zeolite.The crystallization time of NaY zeolite was shortened by 9 h.展开更多
基金supported by the Natural Science Foundation of Tianjin(Grant No.20JCJQJC00060,21JCJQJC00090 and 19JCZDJC38200)the National Natural Science Foundation of China(Grant No.51972230,52172006,22071179,51890864,61835014,51802217,51890865).
文摘Birefringent crystals,which can modulate the polarization of light,are particularly important in optical communication and the laser industry.Here we report the synthesis,structures,optical properties,and theoretical analyses of four rare-earth borates containing BO_(3) groups,i.e.LiRb_(2)YB_(2)O_(6),CaRbYB_(2)O_(6),and Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs).Their structures are not all typical BO_(3) group distributions with large birefringence values,e.g.,being parallel with each other’s distribution or being a regular polygon distribution with a specific form that is parallel with an optical axis.However,their birefringence values exhibit an obvious increase from LiRb_(2)YB_(2)O_(6)(0.038@532 nm)to Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs)(0.103@532 nm).The origin of this birefringence increase was studied by structural analysis and theoretical calculation.First-principles calculations and structure comparisons indicate that the non-symmetry localization of electron density of the Y–O polyhedra has an important contribution to the large birefringence of Li_(2)MY_(4)B_(5)O_(15)(M=Rb,Cs).
基金supported by the National Key Research and Development Program of China(Grant No.2021YFA0718700)the National Natural Science Foundation of China(Grant Nos.52172259 and 52472191)+1 种基金the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(Grant No.2021ZZ127)the Natural Science Foundation of Fujian Province of China(Grant No.2025J010017)。
文摘Conventional methods for quantifying thermoelectric anisotropy rely on precisely aligned crystals,which are time-consuming and error-prone.To address this,we propose a tensor inversion method integrating transport measurements with EBSD-derived Euler angles to determine the intrinsic tensors of as-grown bismuth crystals.This method reconstructs the full second-rank thermoelectric tensors—including electrical resistivity,thermal conductivity,and the Seebeck coefficient—by transforming transport data between the sample coordinate system and the crystal coordinate system.The inverted tensor components of pure bismuth show excellent agreement with reported principal-axis values,validating the accuracy of this method.Moreover,the reversibility of the tensor inversion approach allows for complete visualization of the directional dependence of the thermoelectric figure of merit(zT),revealing its full angular and crystallographic orientation distribution for the first time.This bidirectional framework not only provides a convenient pathway for the reconstruction of intrinsic transport tensors but also enables the prediction of orientation-dependent properties,thereby offering a robust tool for analyzing anisotropic transport behavior and guiding the optimization of thermoelectric performance.
基金financial support provided for this project by the Foundation for the Innovative Research Groups of the National Natural Science Foundation of China(22021004).
文摘Y zeolite is presently used as an important active component in oil refining catalysts.The efficient synthesis of NaY zeolite still faces many huge challenges.Herein,a novel method for the rapid synthesis of nano-plate-like small crystal-sized NaY zeolite through an artificial-fish-reef-breeding negative crystal strategy is reported.It was discovered that cationic polyacrylamide(CPAM)could act as an artificial fish-reef to breed negative crystals,which promoted NaY zeolite nucleation and accelerated the crystallization of NaY zeolite.The crystallization time of NaY zeolite was shortened by 9 h.
