共查询到18条相似文献,搜索用时 296 毫秒
1.
2.
用核磁共振对非晶态中B3+离子的微观结构进行了测定,结合Raman光谱的研究,对Li2O-B2O3-P2O5系统非晶态的性能(电导率、密度等)在P2O5/B2O3比约等于1时产生极值的原因从理论上作了阐明。 相似文献
3.
4.
5.
本文用X射线和差热分析方法对BaO-Li2O-B2O3三元系中的两个截面:BaB2O4-Li2B2O4和BaB2O4-Li2O作了研究。在BaB2O4-Li2B2O4赝二元系中发现了一个新的化合物4BaB2O4·Li2B2O4。化合物在930±3℃由包晶反应形成,并与Li2B2O4形成共晶反应。共晶温度为797±3℃,共晶点组分为79mol%Li2B2O4。在BaB2O4-Li2O截面中也存在化合物4BaB2O4·Li2B2O4,其包晶反应温度从930±3℃随Li2O含量增加下降到908±3℃。在组分60mol%Li2O处形成另一个新的化合物2BaB2O4·3Li2O。该化合物在630±3℃也是由包晶反应形成,并与Li2O和Li2CO3分别形成共晶反应,共晶温度分别为400±3℃和612±3℃。在BaB2O4-Li2B2O4和BaB2O4-Li2O体系中都没有观察到固溶体。用计算机程序分别对化合物4BaB2O4·Li2B2O4和2BaB2O4·3Li2O的X射线粉末衍射图案进行了指标化,其结果:4BaB2O4·Li2B2O4的空间群为Pmma,a=13.033?,b=14.630?,c=4.247?,每个单胞包含两个化合式单位;2BaB2O4·3Li2O的空间群为Pmmm,a=4.814?,b=9.897?,c=11.523?,每个单胞也含有两个化合式单位。
关键词: 相似文献
6.
7.
8.
9.
10.
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。
关键词: 相似文献
11.
The glass forming regions have been determined in the systems P2O5-A2O-MO (A = Li, Na; M = Cu, Cd), P2O5-Bi2O3-Li2O and P2O5-Bi2O3-ZnO. The largest vitreous domain has been found in the ternary diagram P2O5-Bi2O3-ZnO. The variation of the dielectric constants has been followed inside the glass regions. ε'r increases with increasing amount of alkaline oxides and substantially diminishes with increasing percentage of either CuO or CdO. 相似文献
12.
本文采用红外吸收光谱法、X射线散射法和EXAFS方法研究了LiO-Nb2O-SiO2系统非晶态离子导体的结构,认为Nb5+在非晶结构网络中主要是以[NbO6]形式存在。非晶结构随Nb2O5含量的多少而变化。低Nb2O5含量时,[NbO6]相互间以边相连,并与[SiO4]组成多元环后,形成非晶网络结构。高Nb2O5含量时,非晶网络结构主要是以角顶相连的[NbO6]所组成。根据电导测试结果,讨论了结构与电学性能的关系,认为Li2O含量在0.45左右,Nb2O5,含量在0.3左右组成的非晶材料有最高的电导率。
关键词: 相似文献
13.
The enthalpies of formation of a series of high and low temperature phases in the ternary oxide system LixV2O5 have been determined by solution calorimetry. Samples of the former, α-Li0.04V2O5, β-Li0.30V2O5, β'-Li0.48V2O5 and γ-LiV2O5, were prepared by solid state reaction at 650°C. The ambient temperature materials Li0.1V2O5(I), Li0.45V2O5(II) and Li1.03V2O5(III) were prepared by n-butyl lithiation in hexane. The thermochemistries of the two classes of material were examined and related to structural features and to the observed behaviour of V2O5 as a battery cathode material in lithium cells. 相似文献
14.
《Solid State Ionics》1986,21(3):255-261
The electrical conductivity of substituted Li5GaO4 phases was investigated by complex impedance techniques. Substitution by divalent cations to increase the concentration of vacancies in Li5–2xZnxGaO4 did not enhance the ionic conductivity in β-Li5GaO4 -type solid solutions. High Li+ conduction was observed in Li5+xGa1–xMxO4 with M=Mg and Zn in the β-Li5GaO4 structure. The maximum conductivity at 300°C is 4.1 × 10–3 (ω-cm)–1 for Li5.4Ga0.6Zn0.4O4 and 1.3 × 10–3 (ω-cm)–1 for Li5.7Ga0.7Mg 0.3O4. These results are discussed in relation to the structural properties. 相似文献
15.
A wide variety of solid solutions with a structure related to that of γ Li3PO4 may be prepared. These include materials such as lisicon, Li2+2xZn1-xGeO4 and the title systems, many of which have not been studied previously. Conductivity data are presented for eight systems: Li4GeO4-Li3(P, As, V)O4; Li4TiO4-Li3(As, V)O4; Li4GeO4-Li(Ga, Al)O2; Li4GeO4-Li2CaGeO4 and the results compared with those reported in the literature for Li4SiO4-Li3(P, As, V)O4 systems and lisicon. dc polarisation measurements were made on four of the system and it was found that the electronic transference number is 10?4 or less. The materials with the highest conductivity were found in the systems, Li4 (Ge, Ti) O4-Li3 (As, V)O4 with σ ~ (3 to 4) × 10?5 Ω?1 cm?1 at room temperature. It is noted that the systems with the highest conductivity are generally those with the largest unit cell volume. 相似文献
16.
17.
The principal forms of storage-iron in the lamprey,Geotria australis, are haemosiderin in the nephric fold of the larval animal and ferritin in the liver of the adult. Mössbauer spectroscopy of the larval haemosiderin showed that about half of the iron was in the form of ferrihydrite (5Fe2O3.9H2O) with the remainder being in the form of a non-crystalline iron oxyhydroxide, suggesting two modes of biomineralization. The cores of the adult liver ferritin gave spectral parameters indicating the iron to be predominantly in the form of ferrihydrite with about 10% being in a non-crystalline phase. 相似文献
18.
Lithium has been chemically and electrochemically incorporated into V2O5 single crystals. The ESR spectra of these room temperature bronzes are characterized by the same g tensor as α-LixV2O5 high temperature bronzes. This suggests that V2O5 acts as a three-dimensional framework host and that lithium is inserted into the channels of the orthorhombic structure. However, Li+ ions are not randomly distributed into the lattice. A clustering of the paramagnetic centers surrounding these ions is observed, giving an exchange narrowed ESR signal. The usual 29 hyperfine line ESR spectrum of high temperature α-LixV2O5 is again observed after heating the crystal above 300°C showing that these new bronzes convert to the previously reported LixV2O5 bronzes. 相似文献