Calorimetric study and thermodynamic description of Ga-Ge-Li liquid alloys

This publication contains the thermodynamic results received by the drop calorimetry method. The experiments were conducted for four different cross sections, at the temperature of 1080 K. The investigated alloys were as follows: (Ga_0.75Li_0.25)_1-xGe_x, (Ge_0.50Li_0.50)_1-xGa_x, (Ga_0.50Li_0.50)_1-xGe_x, (Ga_0.25Li_0.75)_1-xGe_x. The mixing enthalpy changes measured for all four cross sections of the Ga-Ge-Li system are characterized by negative deviations from the ideal solutions. The Muggianu model with the ternary interaction parameters was applied to elaborate the experimental data of the mixing enthalpy change with the use of the optimized thermodynamic parameters of the binary systems available in the literature.     

Chalcogenide Glasses Based on Germanium Disulfide for Second Harmonic Generation

High second‐order susceptibilities are created by thermal poling in bulk germanium disulfide based chalcogenide glasses. Experimental conditions of the poling treatment (temperature, voltage, time) were optimized for each glass composition. The second‐order nonlinear signals were recorded by using the Maker fringes experiment and a second‐order coefficient χ⁽²⁾ up to 8 pm V^–1 was measured in the Ge₂₅Sb₁₀S₆₅ glass. This value is obtained using a simulation based on accurate knowledge of the thickness of the nonlinear layer. Two mechanisms are proposed to explain the creation of a nonlinear layer under the anode: the formation and the migration of charged defects towards the anode may mainly occur in Ge₂₀Ga₅Sb₁₀S₆₅ and Ge₂₅Ga₅S₇₀ glasses, whereas the migration of Na⁺ ions towards the cathode may be responsible for the accumulation of negative charges under the anode in Ge₃₃S₆₇ and Ge₂₅Sb₁₀S₆₅ glasses. Different electronic conductivity behaviors seem to be at the origin of the phenomenon. In parallel, the potential effect of the poling treatment on the structural and electronic properties is studied using Raman spectroscopy and secondary ion mass spectroscopy measurements.     

Germanium islands embedded in strained silicon quantum wells grown on patterned substrates

Germanium islands were embedded in strained silicon quantum wells in order to provide an improved electron confinement in vicinity of the islands. Growth was performed on relaxed SiGe layers. Patterned substrates were used, favouring lattice relaxation as well permitting the fabrication of small Ge islands at deposition temperatures above 500 °C. Photoluminescence analysis reveals a strongly reduced dislocation related signal. The low temperature spectra are dominated by intense signals from the germanium islands. The origin of these signals were investigated by removing the islands by etching, analysing reference samples without a silicon quantum well, varying the germanium deposition and the growth temperature.     

Third-generation CALPHAD description of pure GeO2 at 1 atm

The thermodynamic properties of crystalline and liquid/amorphous phases of germanium dioxide have been evaluated using DFT calculations and third-generation CALPHAD models. The values for the standard entropies of crystalline and amorphous phases were reassessed through use of the Planck-Einstein approach. This allowed a more physically-based representation of the set of thermodynamic properties of germanium dioxide to be obtained.     

某厂锗煤反射炉收尘系统问题探讨

文章介绍了某厂改造后的锗煤反射炉收尘系统，并对该收尘系统中存在的问题进行了分析和探讨。     

A novel germanium/carbon nanotubes nanocomposite for lithium storage material

A new nanocomposite of Ge/carbon nanotubes (n-Ge/CNTs) was reported by a facile precursor method through a pyrolysis technique. Among it, germanium nanoparticles are encapsulated with a thin layer of amorphous carbon, which benefits to keep a good electronic contact with carbon nanotubes. Germanium nanoparticles are mainly supported inside the carbon nanotubes, which can effectively buffer the volume changes of Germanium. The composite was an effectively mixed (Li⁺ and e⁻) conducting network, which is vital to a quick Li insertion. The composite was shown to exhibit a reversible capacity of about 750 mAh g⁻¹ (74.4 mA g⁻¹) and an improved rate performance, compared with that of CNTs processed as the same condition. Our results demonstrated the composite to be a good active Li-storage material for Li batteries.     

从湿法炼锌渣中回收镓和锗的研究（上）——浸锌渣的还原分选

湿法炼锌浸出渣中含有大量的镓、锗，具有极高的综合同收价值。利用镓、锗所具有的亲铁特性，开发了浸锌渣还原分选富集镓、锗的新工艺。该工艺通过强化浸锌渣的还原过程，使镓、锗定向富集于金属铁中(金属铁是镓、锗的主要载体矿物相)，进而采用磁选的方法从焙烧渣中分离富集镓、锗。研究表明，在温度为1100℃、恒温还原时间为150min的条件下处理含Ga527g／t、Ge305g／t的某厂湿法炼锌浸出渣，可得到镓品位为2164g／t回收率为92．40％，锗品位为1600g／t回收率为99.03％的铁粉。     

石墨炉原子吸收法测定饮用水中痕量锗

探讨了以硝酸钯为基体改进剂,用石墨炉原子吸收法直接测定饮用水中痕量锗的最佳仪器测量条件、方法原理、基体改进剂的用量、准确度、精密度、曲线线性系数、测定下限、线性范围等。结果表明该方法灵敏、准确、稳定性好,加标回收率为96%～105%。     

Broadband Ge/SiGe quantum dot photodetector on pseudosubstrate

We report the fabrication and characterization of a ten-period Ge quantum dot photodetector grown on SiGe pseudosubstrate. The detector exhibits tunable photoresponse in both 3- to 5- μm and 8- to 12- μm spectral regions with responsivity values up to about 1 mA/W at a bias of −3 V and operates under normal incidence radiation with background limited performance at 100 K. The relative response in the mid- and long-wave atmospheric windows could be controlled through the applied voltage.     

Recovery of germanium from real fly ash leachates by ion-exchange extraction

Germanium recovery from real fly ash (FA) leachates was studied using ion-exchange procedures. The procedure was based on germanium complexation with catechol (CAT) in an aqueous solution followed by the retention of the Ge-CAT complex onto a conventional strongly basic anionic resin (IRA-900). A centred composite rotatable design (CCRD) with two factors was employed for experimental design and analysis of the results. The factors examined during sorption tests were CAT amount and resin dosage. Optimum values of these parameters were: a CAT/Ge molar ratio of 9 and resin/Ge dosage of 3, obtaining 96.1% germanium retention. The obtained response surface and mathematical model are significant with high correlation coefficients (R² = 0.8794).The maximum amount of retained germanium was calculated to be 215.5 mg/g resin. The elution of the germanium complex was achieved with acid solutions in an ethanol matrix.