Paramagnetic defects and exchange coupled spins in pristine ultrananocrystalline diamonds
Paramagnetic defects and exchange coupled spins in pristine ultrananocrystalline diamonds
复制标题
DOI：
10.1016/j.diamond.2007.06.003
复制
发表时间：
2007-12-01
影响因子：
4.1
通讯作者：
Vul, A. Ya.
中科院分区：
文献类型：
--
作者：
Osipov, V. Yu.;Shames, A. I.;Vul, A. Ya.
对通过爆轰法制造并通过酸纯化的纳米金刚石样品进行了电子顺磁共振 (EPR) 和磁化率测量。综合酸处理导致磁性杂质的 EPR 信号减弱，并在 T=4 K 时显示出两条弱而窄的 EPR 线，g, =4.26, Delta H-pp= 2.9 mT 和 g(2) =4.00, Delta H-pp = 1.4 mT，间距为 10.4 mT。讨论了在纯化良好的样品中观察到的这种新双峰 EPR 信号的起源。磁化率行为和双峰 EPR 信号（g 类似于 4）表明 S = 1/2 顺磁缺陷的弱反铁磁交换耦合以及 S=1 的孤立二聚体的存在。 (C) 2007 Elsevier B.V. 保留所有权利。
Electron paramagnetic resonance (EPR) and magnetic susceptibility measurements were done on nanodiamond samples fabricated-by the detonation method and purified by acids. Comprehensive acid treatment leads to the reduction of EPR signals of magnetic impurities and revealing two weak and narrow EPR lines with g, =4.26, Delta H-pp= 2.9 mT and g(2) =4.00, Delta H-pp = 1.4 mT at T=4 K, separated by the distance of 10.4 mT. The origin of this new doublet EPR signal observed in the well purified sample is discussed. The magnetic susceptibility behavior and doublet EPR signal (g similar to 4) suggest the weak antiferromagnetically exchange coupling of S = 1/2 paramagnetic defects as well as the presence of isolated dimers with S=1. (C) 2007 Elsevier B.V. All rights reserved.