Uniaxial stress effects on the structural and electronic properties of BaFe2As2 and CaFe2As2

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 CaFe2As2 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.

10 pages, 7 figures

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Cited by in corpus (14)

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• Unfolding of the electronic structure through the induced representations of space groups: Application to Fe-based superconductors
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• Dramatic Changes in the Electronic Structure Upon Transition to the Collapsed Tetragonal Phase in CaFe2As2
• Structural origin of the anomalous temperature dependence of the local magnetic moments in the CaFe${}_2$As${}_2$ family of materials
• Trends in pressure-induced layer-selective half-collapsed tetragonal phases in the iron-based superconductor family $AeA$Fe${}_4$As${}_4$
• Uniaxial pressure effect on the magnetic ordered moment and transition temperatures in BaFe${}_{2-x}{T}_x$As${}_2$ ($T=$Co, Ni)
• The evolution of antiferromagnetic susceptibility to uniaxial pressure in Ba(Fe{1-x}Co{x})2As2
• Ab-initio perspective on structural and electronic properties of iron-based superconductors
• Nesting Induced Large Magnetoelasticity in the Iron Arsenide Systems
• Coexistence of Eu-antiferromagnetism and pressure-induced superconductivity in EuFe2As2 single crystal
• Lattice Parameters Guide Superconductivity in Iron-Arsenides
• Finite temperature and pressure molecular dynamics for BaFe2As2
• Strain-activated structural anisotropy in BaFe2As2