Structural origin of the anomalous temperature dependence of the local magnetic moments in the CaFe${}_2$As${}_2$ family of materials

Abstract

We report a combination of Fe K$\beta$ x-ray emission spectroscopy and $ab$-intio calculations to investigate the correlation between structural and magnetic degrees of freedom in CaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$. The puzzling temperature behavior of the local moment found in rare earth-doped CaFe${}_2$As${}_2$ [\textit{H. Gretarsson, et al., Phys. Rev. Lett. {\bf 110}, 047003 (2013)}] is also observed in CaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$. We explain this phenomenon based on first-principles calculations with scaled magnetic interaction. One scaling parameter is sufficient to describe quantitatively the magnetic moments in both CaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ ($x=0.055$) and Ca${}_{0.78}$La${}_{0.22}$Fe${}_2$As${}_2$ at all temperatures. The anomalous growth of the local moments with increasing temperature can be understood from the observed large thermal expansion of the $c$-axis lattice parameter combined with strong magnetoelastic coupling. These effects originate from the strong tendency to form As-As dimers across the Ca layer in the CaFe${}_2$As${}_2$ family of materials. Our results emphasize the dual local-itinerant character of magnetism in Fe pnictides.

References in corpus (31)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Gap symmetry and structure of Fe-based superconductors
• Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• The challenge of unravelling magnetic properties in LaFeAsO
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide
• A key role for unusual spin dynamics in ferropnictides
• Temperature and pressure-induced spin-state transitions in LaCoO3
• Microscopic origin of magnetism and magnetic interactions in ferropnictides
• Structural collapse and superconductivity in rare earth-doped CaFe2As2
• Revealing the dual nature of magnetism in iron pnictides and iron chalcogenides using x-ray emission spectroscopy
• Dichotomy between large local and small ordered magnetic moment in Iron-based superconductors
• On the multi-orbital band structure and itinerant magnetism of iron-based superconductors
• Stabilization of an ambient pressure, collapsed tetragonal phase in CaFe2As2 and tuning of the orthorhombic / antiferromagnetic transition temperature by over 70 K by control of nano-precipitates
• Antiferromagnetic Correlation and the Pairing Mechanism of the Cuprates and Iron Pnictides : a View From the Functional Renormalization Group Studies
• Spin-state transition in the Fe-pnictides
• Suppression of antiferromagnetic spin fluctuations in the collapsed tetragonal phase of CaFe2As2
• Dramatic Changes in the Electronic Structure Upon Transition to the Collapsed Tetragonal Phase in CaFe2As2
• Abrupt recovery of Fermi-liquid transport by the c-axis collapse in CaFe2(As1-xPx)2 single crystals
• Accounting for spin fluctuations beyond LSDA in the density functional theory
• Effect of doping and pressure on magnetism and lattice structure of Fe-based superconductors
• A novel non-Fermi-liquid state in the iron-pnictide FeCrAs
• Spin-state Crossover Model for the Magnetism of Iron Pnictides
• Uniaxial stress effects on the structural and electronic properties of BaFe2As2 and CaFe2As2
• Thermal expansion of CaFe2As2: effect of cobalt doping and post-growth thermal treatment
• First-principles study of superconducting Rare-earth doped CaFe2As2
• Parallel suppression of superconductivity and Fe moment in the collapsed tetragonal phase of Ca0.67Sr0.33Fe2As2 under pressure

Cited by in corpus (16)

• Pressure-driven phase transition from antiferromagnetic semiconductor to nonmagnetic metal in two-leg ladders $A$Fe${}_2$$X$${}_3$ ($A$=Ba or K, $X$=S or Se)
• Probing the superconducting gap symmetry of $\alpha$-PdBi${}_2$: A penetration depth study
• Local and collective magnetism of EuFe${}_2$As${}_2$
• Evolution from $B_{2g}$ nematics to $B_{1g}$ nematics in heavily hole-doped iron-based superconductors
• Wavefunctions, electronic localization and bonding properties for correlated materials beyond the Kohn-Sham formalism
• Impurity-induced bound states inside the superconducting gap of FeSe
• Magnetic moment evolution and spin freezing in doped BaFe${}_2$As${}_2$
• Role of Hydrogen in the Electronic Properties of CaFeAsH-based Superconductors
• The collapsed tetragonal phase as a strongly covalent and fully nonmagnetic state: persistent magnetism with interlayer As-As bond formation in Rh-doped Ca${}_{0.8}$Sr${}_{0.2}$Fe${}_2$As${}_2$
• Suppressed fluctuations as the origin of the static magnetic order in strained Sr${}_2$RuO${}_4$
• Strong charge and spin fluctuations in La${}_2$O${}_3$Fe${}_2$Se${}_2$
• Influence of the surface symmetry breaking on the magnetism, collapsing and three dimensional dispersion of Co pnictides ACo2As2 (A=Ba, Sr, Ca)
• Ab initio materials physics and microscopic electrodynamics of media
• Anomalous magneto-elastic and charge doping effects in thallium-doped BaFe2As2
• Fluctuating magnetism of Co- and Cu-doped NaFeAs
• Lattice Disorder Effect on Magnetic Ordering of Iron Arsenides