Structural distortion and incommensurate noncollinear magnetism in EuAg4As2

Abstract

Layered pnictide materials have provided a fruitful platform to study various emergent phenomena, including superconductivity, magnetism, charge density waves, etc. Here we report the observation of structural distortion and noncollinear magnetism in layered pnictide EuAg${}_4$As${}_2$ via transport, magnetization, single crystal X-ray and neutron diffraction data. EuAg${}_4$As${}_2$ single crystal shows a structural distortion at 120 K, where two sets of superlattice peaks with the propagation vectors of $q_1=\pm$(0, 0.25, 0.5) and $q_2=\pm$(0.25, 0, 1) emerge. Between 9 K to 15 K, the hexagonal Eu${}^{2+}$ sub-lattice enters an unpinned state, with magnetic Bragg reflections pictured as circular-sectors. Below 9 K, it orders in an incommensurate noncollinear antiferromagnetic state with a well-defined propagation wavevector of (0, 0.1, 0.12), where the magnetic structure is helical along the $c$ axis and cycloidal along the $b$ axis with a moment of 6.4 ${\mu }_B$/Eu${}^{2+}$. Furthermore, rich magnetic phases under magnetic fields, large magnetoresistance, and strong coupling between charge carriers and magnetism in EuAg${}_4$As${}_2$ are revealed.

References in corpus (14)

• High-Temperature Superconductivity in Eu0.5K0.5Fe2As2
• Magnetic structure of EuFe2As2 determined by single crystal neutron diffraction
• Metamagnetic transition in EuFe${}_2$As${}_2$ single crystals
• Interplay of antiferromagnetism, ferromagnetism and superconductivity in EuFe_2(As_1-xP_x)_2 single crystals
• Superconductivity and local-moment magnetism in Eu(Fe${}_{0.89}$Co${}_{0.11}$)${}_2$As${}_2$
• Pressure-induced changes in the magnetic and valence state of EuFe2As2
• Superconductivity and ferromagnetism in EuFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Phase diagram of superconductivity and antiferromagnetism in single crystals of Sr(Fe1-xCox)2As2 and Sr1-yEuy(Fe0.88Co0.12)2As2
• Metallic behavior induced by potassium doping of the trigonal antiferromagnetic insulator EuMn2As2
• NMR Determination of an Incommensurate Helical Antiferromagnetic Structure in EuCo2As2
• Significant change in the electronic behavior associated with structural distortions in the single crystalline SrAg4As2
• Pressure tuning of structural and magnetic transitions in EuAg${}_4$As${}_2$
• Spin correlation in trigonal EuMn${}_2$As${}_2$
• Partial Antiferromagnetic Helical Order in Fe${}_3$PO${}_4$O${}_3$

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• Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg${}_4$Sb${}_2$
• Symmetry of the emergent inductance tensor exhibited by magnetic textures
• Fermiology and transport properties of the proposed topological crystalline insulator SrAg4Sb2
• Mapping the three-dimensional fermiology of the triangular lattice magnet EuAg${}_4$Sb${}_2$
• Quantum oscillations and transport properties of layered single-crystal SrCu${}_4$As${}_2$