Tyryshkin Alexei M, Morton John J L, Ardavan Arzhang, Lyon S A
Department of Electrical Engineering, Princeton University, Princeton, NJ 08522, USA.
J Chem Phys. 2006 Jun 21;124(23):234508. doi: 10.1063/1.2204915.
Over the past 50 years, electron-nuclear double resonance (ENDOR) has become a fairly ubiquitous spectroscopic technique, allowing the study of spin transitions for nuclei which are coupled to electron spins. However, the low spin number sensitivity of the technique continues to pose serious limitations. Here we demonstrate that signal intensity in a pulsed Davies ENDOR experiment depends strongly on the nuclear relaxation time T(1n), and can be severely reduced for long T(1n). We suggest a development of the original Davies ENDOR sequence that overcomes this limitation, thus offering dramatically enhanced signal intensity and spectral resolution. Finally, we observe that the sensitivity of the original Davies method to T(1n) can be exploited to measure nuclear relaxation, as we demonstrate for phosphorous donors in silicon and for endohedral fullerenes N@C(60) in CS(2).
在过去的50年里，电子 - 核双共振（ENDOR）已成为一种相当普遍的光谱技术，可用于研究与电子自旋耦合的原子核的自旋跃迁。然而，该技术对低自旋数的灵敏度仍然存在严重限制。在此，我们证明了脉冲戴维斯ENDOR实验中的信号强度强烈依赖于核弛豫时间T(1n)，对于长T(1n)，信号强度可能会严重降低。我们提出了对原始戴维斯ENDOR序列的改进，克服了这一限制，从而显著提高了信号强度和光谱分辨率。最后，我们观察到原始戴维斯方法对T(1n)的灵敏度可用于测量核弛豫，正如我们在硅中的磷施主以及CS(2)中的内嵌富勒烯N@C(60)上所展示的那样。
