LaCo2B2在過去的研究中，因具有類似鐵基超導體的ThCr2Si2-type結構，且透過Y與Fe參雜而在低溫(Tc~ 4 K)出現超導態而引起了廣泛討論。LaCo2B2和YCo2B2是具有金屬電導性與包利順磁性的材料。
在本篇論文中，我們以核磁共振(NMR)的技術來量測LaCo2B2、 La0.9Y0.1Co2B2和YCo2B2的59Co和11B的NMR頻譜來討論各個樣品的線形、奈特位移及自旋晶格鬆弛時間。
由自旋晶格鬆弛時間的分析可以推測LaCo2B2和YCo2B2的59Co及11B的態密度是相近的，可推測兩者具有類似的電子結構特性。而La0.9Y0.1Co2B2的結果顯示Y原子的參雜作用會大幅提高B 的 2p 態密度, 此結果可能是La0.9Y0.1Co2B2在低溫產生超導態的原因。

In recent studies, LaCo2B2 has attracted lots of attentions because of crystallizing in an iron-based superconductor like ThCr2Si2-type structure and emerging bulk superconductivity (Tc~4 K) by doping Y or Fe atoms. LaCo2B2 and YCo2B2 have been reported as a material with metallic electrical conductivity and Pauli paramagnetic behavior. However, there is little experimental effort associated with their local electrical structure features. In this study, we report an observation in LaCo2B2, La0.9Y0.1Co2B2 and YCo2B2 by using 59Co and 11B nuclear magnetic resonance (NMR) measurements.
The 59Co NMR isotropic knight shift (59Kiso) is positive and close to each other, revealing that the Co-4s electrons and the orbital term are the major source. In addition, the 11B NMR isotropic knight shift (11Kiso)indicates an enhanced trend in B-2s density of state (DOS) and the contribution from orbital term.
With the spin-lattice relaxation rate (1/T1) analyses, we found a strong similarity in the DOS of 59Co and11BbetweenLaCo2B2 and YCo2B2, indicating the uniformity in the electronic structure properties. Moreover, for La0.9Y0.1Co2B2, the 1/T1 analyses revealed a highly uplifted in B-2p DOS owing to the Y substitution effect that may account for the appearance of superconductivity.

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