2015/12/31 by Benjamin A. Frandsen, Michela Brunelli, Katharine Page +5 · 42 citations
Materials Science · Physics and Astronomy · #Ab initio #Ab initio quantum chemistry methods #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Density functional theory #Magnetic and transport properties of perovskites and related materials #Magnetic field #Magnetic structure #Magnetic susceptibility #Magnetization #Materials science #Pair distribution function #Paramagnetism #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin (aerodynamics) #Superexchange #Thermodynamics #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.116.197204
published in Physical Review Letters 116(19), 197204 (American Physical Society)
openalex publication_date 2016/05/11 · arxiv created 2016/05/13 · arxiv updated 2016/05/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a temperature-dependent atomic and magnetic pair distribution function (PDF) analysis of neutron total scattering measurements of antiferromagnetic MnO, an archetypal strongly correlated transition-metal oxide. The known antiferromagnetic ground-state structure fits the low-temperature data closely with refined parameters that agree with conventional techniques, confirming the reliability of the newly developed magnetic PDF method. The measurements performed in the paramagnetic phase reveal significant short-range magnetic correlations on a ∼1 nm length scale that differ substantially from the low-temperature long-range spin arrangement. Ab initio calculations using a self-interaction-corrected local spin density approximation of density functional theory predict magnetic interactions dominated by Anderson superexchange and reproduce the measured short-range magnetic correlations to a high degree of accuracy. Further calculations simulating an additional contribution from a direct exchange interaction show much worse agreement with the data. The Anderson superexchange model for MnO is thus verified by experimentation and confirmed by ab initio theory.