Based on the equilibrium solubility of rubidium of chloride-water binary system and rubidium chloride-hydrochloris acid-water ternary system,a very simple and practical method for the preparation of high purity rubidi...Based on the equilibrium solubility of rubidium of chloride-water binary system and rubidium chloride-hydrochloris acid-water ternary system,a very simple and practical method for the preparation of high purity rubidium chloride was proposed.The purity of this rubidium chloride came up to 99.99%.In the meantime,a rapid and sensitive analytical procedure was set up by using flame atomic absorption spectrometry(AAS),which could be used to monitor the quality of the products whenever necessary.展开更多
Pressure has an important effect on chemical bonds and their chemical properties. The atypical compounds NaCl_(3) and CsF_(3) are predicted to be stable at high pressure and show unique physical and chemical propertie...Pressure has an important effect on chemical bonds and their chemical properties. The atypical compounds NaCl_(3) and CsF_(3) are predicted to be stable at high pressure and show unique physical and chemical properties. By using ab initio random structure searching and density functional theory calculations, we predicted multiple thermodynamically stable atypical compounds, which are RbF_(2), RbF_(3), RbF_(4), and RbF_(5) in the pressure range of 0–300 GPa. In these stable compounds, homonuclear bondings of F_(3), F_(4), and F_(5) species are easily formed. The electron structure calculation showed that except for Fd-3 m phase of RbF_(2), these stable compounds are insulators and F 5 p orbitals play an important role in the Fermi level. It is interesting that the compounds RbF_(5) could be stable at nearly ambient pressure and 0 K which will stimulate experimental studies in the future.展开更多
Copper ion conducting solid electrolyte Rb_(4)Cu_(16)I_(6.5)Cl_(13.5)was prepared by means of mechano-chemical method.The structure and morphology of the powder was investigated by x-ray diffraction and scanning elect...Copper ion conducting solid electrolyte Rb_(4)Cu_(16)I_(6.5)Cl_(13.5)was prepared by means of mechano-chemical method.The structure and morphology of the powder was investigated by x-ray diffraction and scanning electron microscopy.The grain size was estimated to be 0.2-0.9μm and the ionic conductivity at room temperature was approximately 0.206 S/cm.The solid electrolyte Rb_(4)Cu_(16)I_(6.5)Cl_(13.5)was exploited for copper ion beam generation.The copper ion emission current of several nA was successfully obtained at acceleration voltages of 15 kV and temperature of 197℃in vacuum of 2.1×10^(-4)Pa.A good linear correlation between the logarithmic ion current(logI)and the square root of the acceleration voltage(U_(acc))at high voltage range was obtained,suggesting the Schottky emission mechanism in the process of copper ion beam generation.展开更多
In this paper,a non-centrosymmetric compound of Rb_(2)Ca_(2)(SO_(4))_(3)has been synthesized by a high temperature solid-state reaction and high temperature melting method.Single-crystal X-ray diffraction analysis sho...In this paper,a non-centrosymmetric compound of Rb_(2)Ca_(2)(SO_(4))_(3)has been synthesized by a high temperature solid-state reaction and high temperature melting method.Single-crystal X-ray diffraction analysis shows that Rb_(2)Ca_(2)(SO_(4))_(3)crystallizes in the cubic space group of P2_(1)3,and its cell parameters are a=b=c=10.5569(6)Å,Z=4 and V=1176.55(12)Å^(3),respectively.In the crystal structure,SO4 tetrahedra and CaO6 octahedra are connected with each other by a corner-sharing mode to construct the three-dimensional framework of Rb_(2)Ca_(2)(SO_(4))_(3).Optical measurements show that the title compound has a short ultraviolet absorption edge and a moderate second-harmonic generation response.The optical origin is illustrated by the electron band structure calculation.In addition,thermal stability is also studied by virtue of differential thermal/thermogravimetric analysis and powder XRD technique.展开更多
文摘Based on the equilibrium solubility of rubidium of chloride-water binary system and rubidium chloride-hydrochloris acid-water ternary system,a very simple and practical method for the preparation of high purity rubidium chloride was proposed.The purity of this rubidium chloride came up to 99.99%.In the meantime,a rapid and sensitive analytical procedure was set up by using flame atomic absorption spectrometry(AAS),which could be used to monitor the quality of the products whenever necessary.
基金supported by the National Natural Science Foundation of China (Grant No. 11674122)。
文摘Pressure has an important effect on chemical bonds and their chemical properties. The atypical compounds NaCl_(3) and CsF_(3) are predicted to be stable at high pressure and show unique physical and chemical properties. By using ab initio random structure searching and density functional theory calculations, we predicted multiple thermodynamically stable atypical compounds, which are RbF_(2), RbF_(3), RbF_(4), and RbF_(5) in the pressure range of 0–300 GPa. In these stable compounds, homonuclear bondings of F_(3), F_(4), and F_(5) species are easily formed. The electron structure calculation showed that except for Fd-3 m phase of RbF_(2), these stable compounds are insulators and F 5 p orbitals play an important role in the Fermi level. It is interesting that the compounds RbF_(5) could be stable at nearly ambient pressure and 0 K which will stimulate experimental studies in the future.
基金supported by Shenzhen Municipal Science and Technology Innovation Commission(Grant Nos.JCYJ20170818112901473 and GJHZ20200731095604015)the Department of Science and Technology of Guangdong Province,China(Grant Nos.2020A0505100059,2020A1515011531,and 2020A1515011451)by the Ministry of Education and Science of the Russian Federation in the frame of the state assignment(Grant No.FSSN-2020-0003)。
文摘Copper ion conducting solid electrolyte Rb_(4)Cu_(16)I_(6.5)Cl_(13.5)was prepared by means of mechano-chemical method.The structure and morphology of the powder was investigated by x-ray diffraction and scanning electron microscopy.The grain size was estimated to be 0.2-0.9μm and the ionic conductivity at room temperature was approximately 0.206 S/cm.The solid electrolyte Rb_(4)Cu_(16)I_(6.5)Cl_(13.5)was exploited for copper ion beam generation.The copper ion emission current of several nA was successfully obtained at acceleration voltages of 15 kV and temperature of 197℃in vacuum of 2.1×10^(-4)Pa.A good linear correlation between the logarithmic ion current(logI)and the square root of the acceleration voltage(U_(acc))at high voltage range was obtained,suggesting the Schottky emission mechanism in the process of copper ion beam generation.
基金financially supported by the National Natural Science Foundation of China (51972230, 51802217, 61835014, 51890864 and 51890865)the Natural Science Foundation of Tianjin (19JCZDJC38200)the National Key Research and Development Project (2016YFB0402103)
基金the Doctoral Fund(MJY19014)Natural Science Foundation of Fujian Province(2019J01762)President's Fund(103952020020)。
文摘In this paper,a non-centrosymmetric compound of Rb_(2)Ca_(2)(SO_(4))_(3)has been synthesized by a high temperature solid-state reaction and high temperature melting method.Single-crystal X-ray diffraction analysis shows that Rb_(2)Ca_(2)(SO_(4))_(3)crystallizes in the cubic space group of P2_(1)3,and its cell parameters are a=b=c=10.5569(6)Å,Z=4 and V=1176.55(12)Å^(3),respectively.In the crystal structure,SO4 tetrahedra and CaO6 octahedra are connected with each other by a corner-sharing mode to construct the three-dimensional framework of Rb_(2)Ca_(2)(SO_(4))_(3).Optical measurements show that the title compound has a short ultraviolet absorption edge and a moderate second-harmonic generation response.The optical origin is illustrated by the electron band structure calculation.In addition,thermal stability is also studied by virtue of differential thermal/thermogravimetric analysis and powder XRD technique.
