In-plane uniaxial stress effects on the structural and electronic properties of BaFe2As2 and CaFe2As2

Milan Tomić, Harald Olaf Jeschke, Rafael M. Fernandes, Roser Valentí

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Starting from the orthorhombic magnetically ordered phase, we investigate the effects of uniaxial tensile and compressive stresses along a, b, and the diagonal a+b directions in BaFe2As2 and CaFe 2As2 in the framework of ab initio density functional theory (DFT) and a phenomonological Ginzburg-Landau model. While - contrary to the application of hydrostatic or c-axis uniaxial pressure - both systems remain in the orthorhombic phase with a pressure-dependent nonzero magnetic moment, we observe a sign-changing jump in the orthorhombicity at a critical uniaxial pressure, accompanied by a reversal of the orbital occupancy and a switch between the ferromagnetic and antiferromagnetic directions. Our Ginzburg-Landau analysis reveals that this behavior is a direct consequence of the competition between the intrinsic magneto-elastic coupling of the system and the applied compressive stress, which helps the system to overcome the energy barrier between the two possible magneto-elastic ground states. Our results shed light on the mechanisms involved in the detwinning process of an orthorhombic iron-pnictide crystal and on the changes in the magnetic properties of a system under uniaxial stress.

Original languageEnglish
Article number174503
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume87
Issue number17
DOIs
Publication statusPublished - May 9 2013
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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