Is magnetic pinning a dominant mechanism in Nb-Ti?
Is magnetic pinning a dominant mechanism in Nb-Ti?
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磁钉扎是 Nb-Ti 中的主要机制吗？
DOI：
10.1109/20.133372
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发表时间：
1991
影响因子：
2.1
通讯作者：
D. Larbalestier
中科院分区：
文献类型：
--
作者：
L. Cooley;P. Lee;D. Larbalestier
作者比较了人工钉扎中心（APC）复合材料和纳米丝Nb 46.5 wt.% Ti复合材料与传统Nb 48 wt.%的复合材料钛复合材料。APC复合材料的微观结构类似于常规复合材料的微观结构，其中正常金属的条带形成钉扎中心，而纳米细丝复合材料没有内部正常金属，而是在细丝表面处钉扎。APC复合材料相对于B/sub c 2/的钉扎比常规复合材料（21.4 GN/m/sup 3/. 7 T vs. 18.9 GN/m/sup 3/，11 T），这可能是由于钉扎中心的量增加（50 vol. %相对于25体积%）;然而，邻近效应不利地减小了B/sub c2/。在所有三种复合材料中，F/sub p/与（1-B）/sup 3/2/成比例，这表明磁相互作用而不是芯钉扎占主导地位。F/sub p/服从比例关系，因为在常规复合材料中T倾向于T/sub c/，并且在APC复合材料中在宽的温度范围内。在这些制度中，一个钉扎机构也占主导地位，有人建议，钉扎是由集群的钉扎中心，而不是由个别引脚。
The authors compared the pinning behavior of an artificial pinning center (APC) composite and a nanometer-filament Nb 46.5 wt.% Ti composite to that of a conventional Nb 48 wt.% Ti composite. The microstructure of the APC composite resembles that of the conventional composite, where ribbons of normal metal form the pinning centers, whereas the nanometer-filament composite has no internal normal metal but pins at the filament surface instead. The APC composite exhibits much stronger pinning relative to B/sub c2/ than the conventional composite (21.4 GN/m/sup 3/. 7 T vs. 18.9 GN/m/sup 3/, 11 T), which is possibly due to the increased amount of pinning center (50 vol.% vs. 25 vol.%); however, the proximity effect reduces the B/sub c2/ unfavorably. In all three composites, F/sub p/ was proportional to (1-b)/sup 3/2/, which suggests that the magnetic interaction, rather than core pinning, dominates. F/sub p/ obeys a scaling relation as T tends to T/sub c/ in the conventional composite and over a wide range of temperature in the APC composite. In these regimes, one pinning body is also dominant, and it is suggested that pinning is done by clusters of pinning centers rather than by the individual pins.