77Se NMR Evidence for the Development of Antiferromagnetic Spin Fluctuations of π-Electrons in λ-(BETS)2GaCl4
77Se NMR Evidence for the Development of Antiferromagnetic Spin Fluctuations of π-Electrons in λ-(BETS)2GaCl4
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77Se NMR 证明 λ-(BETS)2GaCl4 中 π 电子反铁磁自旋涨落的发展
DOI：
10.1143/jpsj.72.483
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发表时间：
2003
影响因子：
1.7
通讯作者：
N. Toyota
中科院分区：
文献类型：
--
作者：
S. Takagi;D. Maruta;H. Sasaki;H. Uozaki;H. Tsuchiya;Y. Abe;Y. Ishizaki;E. Negishi;H. Matsui;S. Endo;N. Toyota
用~（77）Se NMR研究了超导体（T_{\text{C}} cong 6 K）λ-（BETS）2 GaCl 4（BETS = bis（ethylenedithio）tetraselenafulvalene）在7.1 ~ 100 K正常态下的微观磁性质.从Knight位移和线宽的T依赖性，发现λ-（BETS）2GaCl 4的本征均匀磁化率χ q =0（T）在30 K以下随T的降低而降低.然而，1/（T1 T）没有显示出任何相应的降低，而是恒定地下降到最低T，这表明随着T的降低，反铁磁自旋涨落的贡献增加。对Knight位移和1/（T1 T）进行了定量分析，推导出在低T极限下增强因子K（α）>1.在此基础上，得出了λ-（BETS）2GaCl 4在低温下π电子反铁磁自旋涨落的发展规律.
The microscopic magnetic properties of superconducting (\(T_{\text{C}}\cong 6\) K) λ-(BETS) 2 GaCl 4 (BETS = bis(ethylenedithio)tetraselenafulvalene) have been investigated by 77 Se NMR in the normal state between 7.1 and 100 K on randomly oriented single crystals with κ-(BETS) 2 GaCl 4 as a reference compound. From the T -dependences of the Knight shift and the linewidth, the intrinsic uniform susceptibility χ q =0 ( T ) has been found to decrease with decreasing T below 30 K for λ-(BETS) 2 GaCl 4 . Nevertheless, 1/( T 1 T ) does not show any corresponding decrease but is constant down to the lowest T , which indicates increasing contributions with decreasing T from antiferromagnetic spin fluctuations. The Knight shift and 1/( T 1 T ) have been analyzed quantitatively and the enhancement factor K (α)>1 is deduced in the low- T limit. On the basis of these results, the development of antiferromagnetic spin fluctuations of π-electrons at low T is concluded for λ-(BETS) 2 GaCl 4 .