摘要 等原子 ZrNb 合金的超导转变温度随压力测量到 56.4 GPa。发现 T c ( P ) 依赖性在 42 GPa 附近达到最大值,并且在 5-10 GPa 的压力范围内具有异常行为,最小值很浅。T c (P) 的这种行为类似于早先在纯金属 Nb 上观察到的行为。与最近模型计算的比较表明,纯 Nb 和 ZrNb 合金中 T c ( P ) 行为的特征具有相同的性质,并且是由声子光谱中的高压异常引起的。
Abstract The superconductingtransition temperature of the equiatomic ZrNb alloy is measured in dependence on pressure to 56.4 GPa. The T c ( P ) dependence is found to achieve a maximum around 42 GPa and to have an anomalous behavior with a shallow minimum in the pressure range 5–10 GPa. This behavior of T c ( P ) is similar to that earlier observed on pure metal Nb. A comparison with recent model
摘要 等原子 ZrNb 合金的超导转变温度随压力测量到 56.4 GPa。发现 T c ( P ) 依赖性在 42 GPa 附近达到最大值,并且在 5-10 GPa 的压力范围内具有异常行为,最小值很浅。T c (P) 的这种行为类似于早先在纯金属 Nb 上观察到的行为。与最近模型计算的比较表明,纯 Nb 和 ZrNb 合金中 T c ( P ) 行为的特征具有相同的性质,并且是由声子光谱中的高压异常引起的。
High-strength Zr-Nb-(Cu,Ni,Al) composites with enhanced plasticity
作者:J. Das、W. Löser、U. Kühn、J. Eckert、S. K. Roy、L. Schultz
DOI:10.1063/1.1587254
日期:2003.6.30
Zr73.5Nb9Cu7Ni1Al9.5 and Zr66.4Nb6.4Cu10.5Ni8.7Al8.0 composites of bcc β-Zr(Nb) dendrites embedded in a nanocrystalline matrix were prepared by slow cooling from melt. The increase of Nb content from 6.4 to 9 at. % slightly reduces the strength, but considerably improves the plastic elongation under uniaxial compressive loading from ep=0.6% to 14.8%. The interaction of strain with dendrites and the
The hopping and tunnelling of deuterium trapped by a Zr substitutional atom in Nb have been investigated by elastic energy loss measurements. A Nb0.995Zr0.0045Dx single crystal was excited in its c' and c(44) modes at frequencies between 6.3 and 130 kHz, from 1 to 300 K. The results are compared with previous experiments on the same sample doped with H and on Nb1-yTiy(H,D)(x). The main peak around 150 K due to hopping of D around Zr is accompanied by secondary peaks at lower temperature, like in the alloys previously investigated. This indicates that D las well as H) has two distinct types of occupation around the Zr atom. The most striking feature is the isotope dependence of a narrow peak at 2 K due to H (D) tunnelling. The intensity of the peak with D is more than one order of magnitude higher than that with H. An explanation of this fact is proposed, which only requires the reduction of the tunnelling matrix element when passing from H to D, Tunnelling within both two or four equivalent sites near the Zr atom is considered.
Effect of Zr on growth kinetics, microstructure and microtexture of Nb3Sn by bronze technique