Champion Guillaume, Lalioti Nikolia, Tangoulis Vassilis, Arrio Marie-Anne, Sainctavit Philippe, Villain Françoise, Caneschi Andrea, Gatteschi Dante, Giorgetti Christine, Baudelet François, Verdaguer Michel, Cartier dit Moulin Christophe
Laboratoire de Chimie Inorganique et Matériaux Moléculaires, Université Pierre et Marie Curie, Bât. F74, Case 42, 4 place jussieu, 75252 Paris Cedex 05, France.
J Am Chem Soc. 2003 Jul 9;125(27):8371-6. doi: 10.1021/ja034608u.
We report here the X-ray magnetic circular dichroism (XMCD) study at the Gd M(4,5)- and L(2,3)-edges of two linear magnetic chains involving Gd(III) cations bridged by nitronyl nitroxide radicals. This spectroscopy directly probes the magnetic moments of the 4f and 5d orbitals of the gadolinium ions. We compare macroscopic magnetic measurements and local XMCD signals. The M(4,5)-edges results are in agreement with the J values extracted from the fits of the SQUID magnetic measurements. The L(2,3)-edges signals show that the electronic density in the Gd 5d orbitals depends on the neighbors of the gadolinium cations. Nevertheless, the 5d orbitals do not seem to play any role in the superexchange pathway between radicals through the metal ion proposed to explain the particular magnetic exchange interactions between the radicals in these chains.
我们在此报告了对由硝酰基氮氧自由基桥接的含Gd(III)阳离子的两条线性磁链在Gd M(4,5)和L(2,3)边缘处进行的X射线磁圆二色性（XMCD）研究。这种光谱学直接探测钆离子4f和5d轨道的磁矩。我们比较了宏观磁性测量和局部XMCD信号。M(4,5)边缘的结果与从超导量子干涉仪（SQUID）磁性测量拟合中提取的J值一致。L(2,3)边缘的信号表明，Gd 5d轨道中的电子密度取决于钆阳离子的相邻原子。然而，5d轨道似乎在通过金属离子的自由基之间的超交换途径中不起任何作用，而该途径被认为可以解释这些链中自由基之间特殊的磁交换相互作用。
