stability and anti-disproportionation performance were systematically investigated. The results show that all alloys contain a main phase of ZrMn2 and little impure phase. Crucially, the latticeparameters of ZrMn2 phase increase after V substitution, as well as Mn decrease, leading the equilibriumpressure of dehydrogenation significantly decreases from 2.931 bar (ZrMn2-H) to 0.080 bar (ZrMn1.2V0.6-H) at 200 °C
Structural Novelties in Anionic Cluster Halide Phases. Discrete Tetrahedral A<sub>4</sub>Br<sup>+</sup> Ions in Two New Zirconium Bromide Structures (A = Na−Cs)
作者:Ru-Yi Qi、John D. Corbett
DOI:10.1021/ic970818u
日期:1997.12.1
containers at 850 degrees C afford two series of quaternary clusterphases containing A(4)Br(3+) ions. Cubic (A(4)Br)(2)Zr(6)(Z)Br(18) phases occur for various combinations of A = Na-Cs, Z = Be, B, H, Mn. The combination with A = K, Z = B was structurally characterized (inverse fluorite, Fm&thremacr;m, Z = 4, a = 16.191(2) Å). The 15-e cluster exhibits the appropriate magnetic moment, and this decreases
Abstract Magnetic properties have investigated for the hyperstoichiometric ZrMn2T0.8 (T = Fe, Co, Ni and Cu) system and their hydrides. Hydrogenation is accompanied by a large expansion in unit cell volume, ranging from 22 to 26% with no change in crystal structure. Hydrogenation enhances magnetism in all cases. The system exhibit susceptibility behavior which can be fit to an expression of the form
摘要 研究了超化学计量的 ZrMn2T0.8(T = Fe、Co、Ni 和 Cu)系统及其氢化物的磁性。氢化伴随着晶胞体积的大幅膨胀,范围从 22% 到 26%,晶体结构没有变化。在所有情况下,氢化都会增强磁性。该系统表现出的磁化率行为可以拟合为 X= X 0 +C (T-Θ) ·X o 形式的表达式,对于除 ZrMn2Cu0.8 之外的所有材料都是可观的,其中 xo 可以忽略不计。在 80 K 以下研究的氢化物不寻常的与历史相关的磁性行为很可能是它们自旋玻璃状行为的结果。包括当前结果与其对应物 ZrCrFeT0.8 的结果的比较。
Crystal structure and hydrogen absorption of TixZr1−xMn2
comparison of equilibriumpressures of Ti x Zr 1− x Mn 2 –H 2 system at 269, 298 and 323 K showed that the pressure increased with the titanium content. The absolute values of Δ H and Δ S in α + β two-phase regions monotonously decreased with the titanium content. The variation of Δ S with the titanium content was interpretable by taking into account increased freedom of configuration of hydrogen atoms among
摘要 通过XRD Rietveld 分析和等温测量对Ti x Zr 1− x Mn 2 合金及其x = 0、0.1、0.2 和0.3 的氢化物进行了表征。氢的引入不会改变晶体结构类型(C14 Laves 相),但会导致显着的晶格膨胀。Rietveld 分析中的最佳拟合表明钛原子优先占据锆位点。直接比较 Ti x Zr 1− x Mn 2 –H 2 系统在 269、298 和 323 K 时的平衡压力表明,压力随着钛含量的增加而增加。α+β两相区ΔH和ΔS的绝对值随着钛含量的增加而单调减小。Δ S 随钛含量的变化可以通过考虑不同间隙位点之间氢原子构型自由度的增加来解释。至于Δ S 随氢浓度的变化,发现T 0.3 Zr 0.7 Mn 2 -H 2 系统的绝对值意外下降。我们进一步检测到 T 0.3 Zr 0.7 Mn 2 –H 2 系统的氢饱和α相的异常小尺寸。这两种现象是氢化时发生相分离的征兆。