Dimensionality and magnetic interactions in CaFe₂As₂: An ab initio study

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• 作者：D.A. Tompsett ; G.G. Lonzarich
• 关键词：CaFe₂As₂ ; Fermiology ; Superconductor ; Antiferromagnet
• 刊名：Physica B
• 出版年：2010
• 出版时间：15 May 2010
• 年：2010
• 卷：405
• 期：10
• 页码：2440-2443
• 全文大小：342 K

文摘

We present detailed electronic structure calculations for CaFe₂As₂. We investigate in particular the ‘collapsed’ tetragonal and orthorhombic regions of the temperature–pressure phase diagram and find properties that distinguish CaFe₂As₂ from other Fe-pnictide compounds. In contrast to the tetragonal phase of other Fe-pnictides the electronic structure in the ‘collapsed’ tetragonal phase of CaFe₂As₂ is found to be strongly 3D. By an analysis of the non-interacting susceptibility, χ₀(q), of CaFe₂As₂ and LaFePO we discuss the role of magnetic interactions in iron-pnictides. From this we propose an intuitive explanation for the outstanding question relating to why the predicted antiferromagnetic moment depends strongly on coordinate relaxation and the choice of correlation functional.