Nuclear and Electron Resonance Study of the Paramagnetic Cobalt Ion
Nuclear and Electron Resonance Study of the Paramagnetic Cobalt Ion
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顺磁性钴离子的核与电子共振研究
DOI：
10.1103/physrev.174.385
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
G. Seidel
中科院分区：
文献类型：
--
作者：
S. Choh;G. Seidel
本文研究了Co (nh4) 2 (s2o4) 2·6 h2o中Co 59核的磁共振，该材料的克莱默斯Co 2+离子具有强顺磁性。在低温（1.2 K）条件下，用大磁场（40 ~ 80 kG）对离子的电子矩进行了实验。除了提供超精细和四极相互作用的测量外，实验还确定了由外场诱导的原子核与电子矩的相互作用。与温度无关的Van Vleck顺磁性有关的这种耦合被发现是各向异性的，与原子核与外加场的正常塞曼相互作用的大小相比，σ∥= 0.38±0.02和σ⊥= 0.18±0.05的量级。用估计的硫酸钴铵中Co 2+的晶体场水平对这种相互作用进行了理论计算，与实验结果吻合得很好。为了从核磁共振数据中获得精确计算所需的各种参数信息，还进行了电子自旋共振测量。还观察到超精细相互作用对离子间自旋耦合的影响，并对其进行了讨论。
Magnetic resonance of the Co 59 nucleus has been studied in Co (N H 4) 2 (S O 4) 2· 6 H 2 O, a material in which the Kramers Co 2+ ion is strongly paramagnetic. The experiments were performed on shaped samples with the electronic moments of the ions aligned by a large applied magnetic field (40 to 80 kG) at low temperature (1.2 K). In addition to providing a measurement of the hyperfine and quadrupole interactions, the experiments yielded a determination of the interaction of the nucleus with the electronic moment that is induced by the external field. This coupling, which is related to the temperature-independent Van Vleck paramagnetism, was found to be anisotropic, having the magnitude σ∥= 0.38±0.02 and σ⊥= 0.18±0.05 as compared with the size of the normal Zeeman interaction of the nucleus with the applied field. A theoretical calculation of this interaction using the estimated crystal-field levels of Co 2+ in the cobalt ammonium sulfate is in satisfactory agreement with experiment. Electron spin resonance measurements were also performed to obtain information of various parameters required for accurate calculations from the NMR data. The influence of hyperfine interactions on the spin-spin coupling among ions was also observed and is discussed.