Paramagnetic relaxation of spin polarized 3He at coated glass walls
Paramagnetic relaxation of spin polarized 3He at coated glass walls
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自旋极化 3He 在镀膜玻璃壁上的顺磁弛豫
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
A. Simón
中科院分区：
文献类型：
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作者：
A. Deninger;Werner Heil;Ernst W. Otten;M. Wolf;R. Kremer;A. Simón
摘要：在这三篇关于壁松弛的系列论文中的第二篇，
3 He自旋，我们讨论了金属涂层玻璃细胞的弛豫方面，
费米面上顺磁传导电子的超精细耦合
面这与涂层的功函数的平方成比例，
从而也具有其He吸附能。在这个意义上，我们研究
具有特别低的功函数和吸附能的涂层，即
Cs和Cs-低氧化物。虽然我们观察到弛豫速率的抑制
与裸露的派热克斯玻璃和熔融石英壁相比增加两个数量级，
它们的温度依赖性仍然显示出与
观察到的裸基板，而不是T 3/2的依赖预期为
金属表面。从这一发现中，我们得出结论，一方面，
表面覆盖不完全，另一方面，
碱性表面本身非常慢。这一发现也得到了支持，
通过基于正常情况下测量的弛豫率的半经验估计
金属表面，然后与各自的吸附依赖性重新缩放
能源
Abstract.In this second in a series of three papers on wall relaxation of
3He-spins we discuss relaxation in metal-coated glass cells in terms of
hyperfine coupling to paramagnetic conduction electrons at the Fermi
surface. This scales with the square of the work function of the coating and
thereby also with its He-adsorption energy. In this sense we investigate
coatings with particularly low work function and adsorption energy, namely
Cs and Cs-suboxides. Although we observe a suppression of relaxation rates
by two orders of magnitude as compared to bare Pyrex and fused silica walls,
their temperature dependence still shows the same Arrhenius dependence as
observed for bare substrates, instead of a T 3/2 dependence expected for
a metallic surface. From this finding we conclude that, on one hand, the
surface coverage is not complete and, on the other hand, the relaxation at
the alkali surface itself is extremely slow. This finding is supported, too,
by a semi-empirical estimate based on measured relaxation rates at ordinary
metal surfaces, rescaled then with the respective dependence on adsorption
energy.