Spin reorientation and Ce-Mn coupling in antiferromagnetic oxypnictide CeMnAsO

Abstract

Structure and magnetic properties of high-quality polycrystlline CeMnAsO, a parent compound of the "1111"-type oxypnictides, have been investigated using neutron powder diffraction and magnetization measurements. We find that CeMnAsO undergoes a C-type antiferromagnetic order with Mn${}^{2+}$ ($S=5/2$) moments pointing along the \textit{c}-axis below a relatively high Néel temperature of $T_{\mathrm{N}}=345$ K. Below $T_{\mathrm{SR}}=35$ K, two instantaneous transitions occur where the Mn moments reorient from the $c$-axis to the \textit{ab}-plane preserving the C-type magnetic order, and Ce moments undergo long-range AFM ordering with antiparallel moments pointing in the \textit{ab}-plane. Another transition to a noncollinear magnetic structure occurs below 7 K. The ordered moments of Mn and Ce at 2 K are 3.32(4) ${\mu }_B$ and 0.81(4)${\mu }_B$, respectively. We find that CeMnAsO primarily falls into the category of a local-moment antiferromagnetic insulator in which the nearest-neighbor interaction ($J_1$) is dominant with $J_2<J_1/2$ in the context of $J_1-J_2-J_c$ model. The spin reorientation transition driven by the coupling between rare earth Ce and transition metal seems to be common to Mn, Fe and Cr ions, but not to Co and Ni ions in the iso-structural oxypnictides. A schematic illustration of magnetic structures in Mn and Ce sublattices in CeMnAsO is proposed.

8 pages, 6 figures, two tables, 38 references, Physical Review B, Accepted and in production

References in corpus (8)

• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Interplay of Rare Earth and Iron magnetism in RFeAsO with R = La, Ce, Pr, and Sm: A muon spin relaxation study and symmetry analysis
• Electronic structure and Magnetism in BaMn${}_2$As${}_2$ and BaMn${}_2$Sb${}_2$
• A variable temperature study of the crystal and magnetic structures of the giant magnetoresistant materials LnMnAsO (Ln = La, Nd)
• Nd induced Mn spin-reorientation transition in NdMnAsO
• Heavy Fermion Quantum Criticality and Destruction of the Kondo Effect in a Nickel Oxypnictide
• Local moments and symmetry breaking in metallic PrMnSbO
• Neutron-scattering measurements of the spin excitations in LaFeAsO and Ba(Fe${}_{0.953}$Co${}_{0.047}$)${}_2$As${}_2$: Evidence for a sharp enhancement of spin fluctuations by nematic order

Cited by in corpus (7)

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• Crystal growth, microstructure and physical properties of SrMnSb${}_2$
• Atomic-Scale Magnetic Toroidal Dipole under Odd-Parity Hybridization
• Structure-Property Relationship in Layered BaMn2Sb2 and Ba2Mn3Sb2O2
• Effect of antifluorite layer on the magnetic order in Eu-based 1111 compounds, EuTAsF (T = Zn, Mn, and Fe)
• PhD Thesis: Electronic correlations in multiorbital systems