Krishnamurthy V V, Lang J C, Haskel D, Keavney D J, Srajer G, Robertson J L, Sales B C, Mandrus D G, Singh D J, Bilc D I
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2007 Mar 23;98(12):126403. doi: 10.1103/PhysRevLett.98.126403. Epub 2007 Mar 20.
We combine x-ray magnetic circular dichroism spectroscopy at Fe L2,3 edges, at Eu M4,5 edges, x-ray absorption spectroscopy (XAS) investigation of Eu valence, and local spin density calculations, to show that the filled skutterudite Eu0.95Fe4Sb12 is a ferrimagnet in which the Fe 3d moment and the Eu2+ 4f moment are magnetically ordered with dominant antiferromagnetic coupling. From Eu L3 edge XAS, we find that about 13% of the Eu have a formal valence of 3+. We ascribe the origin of ferrimagnetism at a relatively high transition temperature TC of 85 K in Eu0.95Fe4Sb12 to f-electron interaction with the nearly ferromagnetic [Fe4Sb12]2.2- host lattice.
我们结合了在铁的L2、3边缘以及铕的M4、5边缘处的X射线磁圆二色光谱、铕价态的X射线吸收光谱（XAS）研究以及局域自旋密度计算，以表明填充式方钴矿Eu0.95Fe4Sb12是一种亚铁磁体，其中铁的3d磁矩和Eu2+的4f磁矩呈磁有序排列，且主要为反铁磁耦合。通过铕L3边缘XAS，我们发现约13%的铕具有+3的形式价态。我们将Eu0.95Fe4Sb12在相对较高的85K转变温度TC下产生亚铁磁性的原因归因于f电子与近铁磁性的[Fe4Sb12]2.2-主晶格之间的相互作用。
