Abstract
We present high temperature inelastic neutron scattering and magnetic susceptibility measurements of the antiferromagnetic insulator LaMnPO that are consistent with the presence of two-dimensional magnetic correlations up to a temperature K, the Néel temperature. Optical transmission measurements show the K direct charge gap eV has decreased only marginally by 500 K and suggest it decreases by only 10% at . Density functional theory and dynamical mean-field theory calculations reproduce a direct charge gap in paramagnetic LaMnPO only when a strong Hund's coupling eV is included, as well as on-site Hubbard eV. Our results show that LaMnPO is a Mott-Hund's insulator, in which the charge gap is rather insensitive to antiferromagnetic exchange coupling.
- Received 23 February 2014
- Revised 2 November 2014
DOI:https://doi.org/10.1103/PhysRevB.90.180403
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