Degenerate ground state in the classical pyrochlore antiferromagnetNa3Mn(CO3)2Cl

2018/10/11 by Kazuhiro Nawa, Daisuke Okuyama, Maxim Avdeev +7 · 6 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Atomic physics #Chemistry #Condensed matter physics #Crystallography #Degenerate energy levels #Ground state #Heat capacity #Magnetic field #Magnetization #Multiferroics and related materials #Order (exchange) #Physics #Physics of Superconductivity and Magnetism #Pyrochlore #Quantum mechanics #Spins #Thermodynamics #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.98.144426

published in Physical review. B./Physical review. B 98(14) (American Physical Society) · 9 pages, 7 figures, accepted to PRB

arxiv created 2018/10/11 · openalex publication_date 2018/10/18 · arxiv updated 2018/10/19 · openalex created_date 2018/10/26 · openalex updated_date 2026/08/05

Abstract

In an ideal classical pyrochlore antiferromagnet without perturbations, an infinite degeneracy in a ground state leads to the absence of magnetic order and a spin-glass transition. Here we present Na₃Mn(CO₃)₂Cl as a new candidate compound where classical spins are coupled antiferromagnetically on the pyrochlore lattice and report its structural and magnetic properties. The temperature dependences of the magnetic susceptibility and heat capacity and the magnetization curve are consistent with those of an S=5/2 pyrochlore lattice antiferromagnet with nearest-neighbor interactions of 2 K. Neither an apparent signature of a spin-glass transition nor magnetic order is detected in magnetization and heat capacity measurements or powder neutron diffraction experiments. On the other hand, antiferromagnetic short-range order of the nearest neighbors is evidenced by the Q dependence of the diffuse scattering which develops around 0.85\phantom\rule0.16em0ex\AA^\ensuremath-1. A high degeneracy near the ground state in Na₃Mn(CO₃)₂Cl is supported by the magnetic entropy, estimated as almost 4\phantom\rule0.16em0exJ\phantom\rule0.16em0exK^\ensuremath-2\phantom\rule0.16em0exmol^\ensuremath-1 at 0.5 K.

Citations

• Spin Hamiltonian, order out of a Coulomb phase, and pseudocriticality in the frustrated pyrochlore Heisenberg antiferromagnetFeF3
• Nematic, vector-multipole, and plateau-liquid states in the classicalO(3)pyrochlore antiferromagnet with biquadratic interactions in applied magnetic field
• Recent advances in magnetic structure determination by neutron powder diffraction
• Die Berechnung optischer und elektrostatischer Gitterpotentiale
• Dynamical Theory of Crystal Lattices
• VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data
• Spin Freezing in Geometrically Frustrated Antiferromagnets with Weak Disorder
• Theory of paramagnetic scattering in highly frustrated magnets with long-range dipole-dipole interactions: The case of theTb2Ti2O7pyrochlore antiferromagnet
• Simulation of electrostatic systems in periodic boundary conditions. I. Lattice sums and dielectric constants
• Quantum Spin Liquids