X-ray magnetic-circular-dichroism spectra on the superparamagnetic transition-metal ion clusters Mn12 and Fe8 -: art. no. 132413
X-ray magnetic-circular-dichroism spectra on the superparamagnetic transition-metal ion clusters Mn12 and Fe8 -: art. no. 132413
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DOI：
10.1103/physrevb.64.132413
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发表时间：
2001-10-01
影响因子：
3.7
通讯作者：
Borgatti, F
中科院分区：
文献类型：
--
作者：
Ghigna, P;Campana, A;Borgatti, F
分子超顺磁体[Mn 12 O 12（CH 3COO）（16）（H2O）（24）]的X射线磁圆二色性（XMCD）光谱。2CH（3）COOH。4 H（2）O（简称Mn 12）和[Fe 8 O 2（OH）（12）（tacn）（6）]Br-2。9 H（2）O（简称Fe 8）。在Mn-12化合物的Mn-L-III、L-II边和Fe_8化合物的Fe-L-III、L-II边进行了XMCD测量。对于Fe_（12）和Fe_（18），从二向色性信号中得到了很低或可忽略的[L-z]：据我们所知，这是第一个直接的实验证据，证明了在这些体系中晶体场对角动量的猝灭。Fe 8的二色性光谱的定量分析得到[L-z]/[S-z] = 0.02（1）。
X-ray magnetic-circular-dichroism (XMCD) spectra on the molecular superparamagnets [Mn12O12(CH3COO)(16)(H2O)(24)]. 2CH(3)COOH . 4H(2)O (in short Mn12) and [Fe8O2(OH)(12)(tacn)(6)]Br-2. 9H(2)O (in short Fe8) are presented. The XMCD measurements have been per-formed at the Mn-L-III,L-II edges in the Mn-12 compound and at the Fe-L-III,L-II edges in the Fe8 compound. For Fe8 the typical two-peak structure of Fe(III) compounds is found. For Mn12 and Fe8, from the dichroic signals a very low or negligible [L-z] was obtained: to the best of our knowledge, this is the first direct experimental evidence of the quenching of the angular momentum by the crystal field in these systems. Quantitative analysis of the dichroic spectra for Fe8 yielded [L-z]/[S-z] = 0.02(1).