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Single phase of Li3AlN2 was prepared from the mixture of Li3N/AlN = 1.2 to 1.5 in molar ratio at 700°C and at 900°C. It crystalizes in the cubic system derived from antifluorite-type structure having the lattice parameter . It is a pure ionic conductor having conductivity of 5 × 10?8ω?1cm?1 at room temperature and an activation energy of 52 kJ/ mol. Its decomposition voltage was 0.85 V at 104°C. The TiS2/Li3AlN2/Li cell could be discharged at a constant current of 45 μA/cm2 at 104°C. 相似文献
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The ionic conductivity of Li3N crystals doped with various metal ions (magnesium, copper and aluminum) or hydrogen has been investigated. The metal ions have a negative effect on the conductivity whereas hydrogen increases it. The intrinsic Li+ ionic conductivity of pure Li3N is (2·-4)×10-4Ω-1cm-1 at room temperature with an activation energy of 0.26?0.27 eV. Doping with hydrogen to a maximum level of 0.5?1.0 atom% results in a conductivity of 6×10-3Ω-1cm-1 and an activation energy which has been lowered to 0.20 eV. A model is proposed for the action of hydrogen whereby the Li-N bonds next to an NH2- group are weakened thereby facilatating the creation of Li+ Frenkel defects and the vacancy migration. Hydrogen-doped Li3N is termed an enhanced intrinsic conductor. 相似文献
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本文用固相反应烧结制备出Li2Mo2O6多晶材料。经X射线分析、红外光谱和电子顺磁共振谱(EPR)的研究,确定了它的结构是Li2Mo2O4和MoO2两个晶相组成的烧结体。钼离子以四价状态存在于MoO2晶相结构中。采用交流阻抗谱分析了晶界与温度变化的相关性。测得了样品的ln(σ总T)-1/T 曲线是由两段直线和一段曲线所组成;总电导率化能σ27℃=1.36×10-3(Ω·cm)-1,σ115℃=1.49×10-3(Ω·cm)-1,σ300℃=9.71×10-3(Ω·cm)-1,σ370℃=2.42×10-3(Ω·cm)-1;电导活化能E1=0.043eV,E2=0.235eV,E平均=0.76eV。采用维格纳极化电池法测得电子电导率σe,σe27℃=2.240×10-5(Ω·cm)-1,σe300℃=4.476×10-3(Ω·cm)-1。实验证明,室温下材料为固体电解质,300℃附近为良好的离子与电子混合导体。
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本文在室温到300℃的温度范围内研究了Li4SiO4-Li3VO4和Li4GeO4-Li4SiO4-Li3VO4体系中的离子导电性,发现γII相固溶体Li3+xV1-xSixO4是好的锂离子导体。所研究的成分中Li3.3V0.7Si0.3O4的离子电导率最高,室温下为1×10-5Ω-1·cm-1,在42—192℃的电导激活能为0.36eV,电子电导率可以忽略,因而这是迄今所发现的最好的锂离子导体之一。粗略确定了Li4GeO4-Li4SiO4-Li3VO4三元系中电导率高的范围,发现在Li3.5V0.5Ge0.5O4中Si部分取代Ge可以使电导率进一步提高,Li3.5V0.5Ge0.4Si0.1O4的室温电导率可达1.3×10-5Ω-1·cm-1,电导激活能为0.40eV。
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In the system Li4SiO4-Li3AsO4, Li4SiO4 forms a short range of solid solutions containing up to 14 to 20% Li3AsO 4, depending on temperature, and γ-Li3AsO4 forms a more extensive range of solid solutions containing up to ≈55% Li4SiO4. The Li4SiO4-Li3AsO4 phase diagram has been determined and is of binary eutectic character. The ac conductivity of polycrystalline samples was measured over the range 0 to at least 300°C for nine different compositions. The two solid solution series have much higher conductivity than the pure end-members; maximum conductivity was observed in the γ-Li3AsO4 solid solutions containing ≈40 to 55% Li4SiO4, with values of at 20°C rising to ≈0.02 Ω?1 cm?1 at 300°C. These values are comparable to those found in the system Li4SiO4-Li3PO4. The variation with composition of the Arrhenius prefactor and activation energy has been interpreted in terms of the mechanisms of conduction. Li3AsO4 is a poor conductor essentially because the number of mobile Li+ ions is very small. This number, and hence the conductivity, increases dramatically on forming solid solutions with Li4SiO4, by the creation of interstitial Li+ ions. At ≈40 to 55% Li4SiO4, the number of mobile Li+ ions appears to be optimised. An explanation for the change in activation energy of conduction at ≈290°C in Li4SiO4 and at higher temperatures in Li4SiO4 solid solutions is given in terms of order-disorder of the Li+ ions. 相似文献
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Polyion complexes between poly(sodium acrylate) and polybrene , or poly(2-acrylamino-2-methylpropane sulfonate) and were synthesized. After removing sodium bromide, these polymers were dispersed with LiClO4, and their Li+ conductivities were measured at 80 ~ 200°C. Their ionic conductivities changed from 10-3 to 10-8 S cm-1 at 100 ~ 200°C. These polymers and poly(ethylene oxide) dispersed with LiBF4 were used as solid electrolytes of Li-activated carbon fiber (ACF) batteries and ACF-ACF capacitor. 相似文献
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The ν4 infrared and Raman bands of CH3Cl were analyzed simultaneously. A direct fit yielded a complete set of constants for CH335Cl, including A0 = 5.20530 ± 0.00010 cm?1 and DK = (8.85 ± 0.13) × 10?5cm?1. For CH337Cl an incomplete set of constants was obtained from the infrared band, and A0 = 5.2182 ± 0.0010 cm?1 was estimated by curve fitting of the Raman spectrum. The resulting equilibrium structure is , , and <(HCH) = 110°.35 ± 0°.05. 相似文献
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Lithium ion conductivity in solid solutions of Li7Ta1-xNbxO6, Li7Ta1-xBixO6, Li7+xTa1-xZrxO6 and Li7-2xCaxTaO6 has been measured as a function of temperature and composition using the complex impedance method. At 200°C the conductivities of Li7Ta0.7Nb0.3O6, Li7.4Ta0.6Zr0.4O6 and Li6.6Ca0.2TaO6 are 4.3 × 10-4(ωcm)-1, 3.0 × 10-4(ωcm)-1, 4.0 × 10-4(ωcm)-1 and 1.6 × 10-4(ωcm)-1 respectively. The results are discussed in relation to structural properties. 相似文献
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本文研究了Lisicon(锗酸锌锂)单晶的Li+离子电导率。发现各结晶学方向电导率之间的关系为σb≤σa≤σc≤σ[110],但各向异性不强。晶体中Li含量对电导率有明显的影响,当Li/Zn比率由6.7变到9.2时,300℃a方向电导率由4.3×10-2Ω-1·cm-1增加到1.25×10-1Ω-1·cm-1,logσT对1/T的曲线显示出三个转变点,分别在~80℃,~140℃和~300℃。电导的激活能分别为0.50—0.58eV(25—80℃),0.92eV(~80—140℃),0.64eV(~140—300℃)和0.36eV(>300℃),极化实验表明单晶的电子电导可以忽略。
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Thin films obtained with glasses of the B2S3Li2S and B2S3Li2SLiI systems, using a vacuum evaporation technique have been investigated. In each system, amorphous thin films and starting glasses have the same composition and similar conductivities, about 10?4 and 10?3Ω?1cm?1 respectively at 25°C. The deposition rate was in both cases 140 Å s?1. However, a thermal treatment at 90°C of the thin films containing lithium iodide enhances the conductivity by a factor of 10 and leads to lower activation energy (0.18 eV). This behavior has been identified as a Phipps effect and can be attributed to a quick ion diffusion along thin film - substrate interface. This interfacial region was found to show unique conduction properties including a very low Li+ migration enthalpy. 相似文献
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Crystals of Li2NiP2S6 may be prepared by direct combination of stoichiometric amounts of Li2S, phosphorus, nickel and sulphur in a temperature gradient towards 750°C. The structure determined by X-ray powder diffraction is monoclinic C2/m with , and is based on the NiPS3 layer structure with two Ni atoms substituted by lithium, and with two lithium atoms in the van der Waals gap. 相似文献
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The resistivity, thermoelectric power and Hall constant in the temperature range of 78–830 K were determined for polycrystalline Th3As4 samples obtained by annealing thin thorium slabs in arsenic vapour. The samples examined were n-type semiconductors with a carrier concentration ranging from 1.0 × 1018cm?3 to 2.8 × 1018 cm?3 for which the effective mass was found to be equal to 0.55–0.76m0. The Hall mobility, about 450cm2V?1s?1 at room temperature, obeys a law at high temperatures. On the basis of the electrical measurements the forbidden gap of Th3As4 was found to be equal to 0.43 eV. 相似文献
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H. Endres R. Harms H.J. Keller W. Moroni D. Nöthe M.H. Vartanian Z.G. Soos 《Journal of Physics and Chemistry of Solids》1979,40(8):591-596
Upon oxidation of 5.10-dihydro-5.10-diethylphenazine (E2P) with iodine golden-green lustrous crystals of a compound with stoichiometry E2P.I1.6 were isolated. The compound crystallizes in the tetragonal space group D42 with and . The E2P and I form interpenetrating incommensurate sublattices along c, with an iodine repeat distance of 9.7 Å. Static susceptibility measurements at room temperature give χg = + 0.994 × 10?6g?1 × cm3. This corresponds to one unpaired electron spin per two formular units. Single-crystal EPR indicates that the paramagnetism is associated with weakly interacting E2P+ cation radicals. The 300K-d.c. conductivity of 3×10?2Ω?1cm?1 and activation energy of 0.17±0.02eV for single crystals is consequently associated with the polyiodide chains, and not with the E2P+ cation radicals. 相似文献
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Keu Hong Kim Sung Han Lee Jae Shi Choi 《Journal of Physics and Chemistry of Solids》1985,46(3):331-338
Electrical conductivities of αFe2O3 containing 1 2, 2 3 and 3 8 mol% CdO were measured in the temperature range of 300 to 1300°C at Po2's of 10?9 to 10?1 atm Plots of log at constant Po2's were found to be linear with an inflection at temperatures around 500°C and higher Po2's than 1 × 10?4 atm. The activation energies obtained by the least-squares method were 1 34 eV for the intrinsic region and 0 51 eV for the extrinsic region on αFe2O3 doped with 38 mol% CdO The extrinsic conductivities disappeared at lower Po2's than 1 × 10-4atm, and the intrinsic conduction appeared on the specimens investigated The electrical conductivities decreased with increasing amount of CdO doping The predominant defects in this system are believed to be interstitial Fe2 for the intrinsic region and oxygen vacancies for the extrinsic region. 相似文献
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The infrared absorption spectrum of a single crystal of MoSe2 is reported. A damped oscillator fit to the fundamental band gives the transverse optic frequency, at 300° K and at 77° K. The static and high frequency dielectric constants have been determined as Ks = 16.81 and K∞ = 10.24 respectively. An absorption band appears in the i.r. spectrum at 482 cm-1, and has been attributed to the oxygen impurity in the crystal. 相似文献