The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterizati...The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.展开更多
The results of the metal-insulator transition （MIT） induced by impurity concentration are presented in the case of metallic and insulating samples 70Ge：Ga p-type. The eight samples studied have Ga concentrations N ...The results of the metal-insulator transition （MIT） induced by impurity concentration are presented in the case of metallic and insulating samples 70Ge：Ga p-type. The eight samples studied have Ga concentrations N ranging from 1.848 × 1017 to 1.912 × 10^17 cm-3. The conductivity measurements were carried out at low temperature in the range 1 to 0.019 K. We provide physical explanations to explain the behaviors of the temperature dependence of the electrical conductivity in both sides of the MIT. The data are for a 70Ge：Ga sample prepared and reported by Itoh et aL in Ref. [Itoh K M, Watanabe M, Ootuka Y, et al. J Phys Soc Jpn, 2004, 73（1）： 173].展开更多
Ge-Ga-Ag-S chalcogenide glasses with the composition Ge30Ga3Ag4S63 were obtained by the conventional melt-quenching method. According to the visible-infrared and infrared spectra, Ge30Ga3Ag4S63 chalcogenide glass poss...Ge-Ga-Ag-S chalcogenide glasses with the composition Ge30Ga3Ag4S63 were obtained by the conventional melt-quenching method. According to the visible-infrared and infrared spectra, Ge30Ga3Ag4S63 chalcogenide glass possesses wide transmittance window from 510 nm in the visible region up to 11.5 μm in the infrared region. And the present glass has better glass-forming ability (the difference between glass transition temperature and the peak temperature of crystallization is larger than 100 ℃). Utilizing maker-fringe technique, a prominent second-harmonic generation was observed in Ge30Ga3Ag4S63 chalcogenide glass after irradiated by an electron beam (Accelerating voltage: 25 kV; Irradiating current: 15 nA; Irradiating time: 10 min). And the mechanism of second-harmonic generation in the Ge-Ga-Ag-S system glasses was discussed.展开更多
为制备适用于68Ge-68Ga发生器的吸附剂,用热HNO3氧化金属锡制备SnO2,对SnO2吸附剂的制备工艺及其性能进行了研究。制备得到以SnO2作为吸附剂的68Ge-68Ga发生器,并对其吸附行为与淋洗效率进行了研究。结果表明,600℃高温焙烧获得的SnO2...为制备适用于68Ge-68Ga发生器的吸附剂,用热HNO3氧化金属锡制备SnO2,对SnO2吸附剂的制备工艺及其性能进行了研究。制备得到以SnO2作为吸附剂的68Ge-68Ga发生器,并对其吸附行为与淋洗效率进行了研究。结果表明,600℃高温焙烧获得的SnO2适于用作68Ge-68Ga发生器的吸附剂,其对68Ge有较好的选择性吸附,用8 mL 1 mol/L HCl淋洗,68Ga的淋洗效率为60%~80%,68Ge的漏穿率大部分为10-3%量级。展开更多
Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the ...Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the loss of <sup>68</sup>GeCl<sub>4</sub> during the processing and storage, resulting a stable <sup>68</sup>Ge source.展开更多
基金supported by the National Natural Science Foundation of China (21975032 and 21571020)the National Key Research and Development Program of China (2018YFA0702100)
文摘The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.
文摘The results of the metal-insulator transition （MIT） induced by impurity concentration are presented in the case of metallic and insulating samples 70Ge：Ga p-type. The eight samples studied have Ga concentrations N ranging from 1.848 × 1017 to 1.912 × 10^17 cm-3. The conductivity measurements were carried out at low temperature in the range 1 to 0.019 K. We provide physical explanations to explain the behaviors of the temperature dependence of the electrical conductivity in both sides of the MIT. The data are for a 70Ge：Ga sample prepared and reported by Itoh et aL in Ref. [Itoh K M, Watanabe M, Ootuka Y, et al. J Phys Soc Jpn, 2004, 73（1）： 173].
基金Project (50125205) supported by the National Natural Science Foundation of China Project (SYSJJ2004-14) by Key Laboratory of Silicate Materials Science and Engineering (Wuhan University of Technology) Ministry of Education
文摘Ge-Ga-Ag-S chalcogenide glasses with the composition Ge30Ga3Ag4S63 were obtained by the conventional melt-quenching method. According to the visible-infrared and infrared spectra, Ge30Ga3Ag4S63 chalcogenide glass possesses wide transmittance window from 510 nm in the visible region up to 11.5 μm in the infrared region. And the present glass has better glass-forming ability (the difference between glass transition temperature and the peak temperature of crystallization is larger than 100 ℃). Utilizing maker-fringe technique, a prominent second-harmonic generation was observed in Ge30Ga3Ag4S63 chalcogenide glass after irradiated by an electron beam (Accelerating voltage: 25 kV; Irradiating current: 15 nA; Irradiating time: 10 min). And the mechanism of second-harmonic generation in the Ge-Ga-Ag-S system glasses was discussed.
文摘为制备适用于68Ge-68Ga发生器的吸附剂,用热HNO3氧化金属锡制备SnO2,对SnO2吸附剂的制备工艺及其性能进行了研究。制备得到以SnO2作为吸附剂的68Ge-68Ga发生器,并对其吸附行为与淋洗效率进行了研究。结果表明,600℃高温焙烧获得的SnO2适于用作68Ge-68Ga发生器的吸附剂,其对68Ge有较好的选择性吸附,用8 mL 1 mol/L HCl淋洗,68Ga的淋洗效率为60%~80%,68Ge的漏穿率大部分为10-3%量级。
文摘Two new systems have been presented for the extraction separation of <sup>68</sup>Ga from irradiated Ga<sub>2</sub>O<sub>3</sub> target after proton bombardment. It could avoid the loss of <sup>68</sup>GeCl<sub>4</sub> during the processing and storage, resulting a stable <sup>68</sup>Ge source.
