Search For a Consistent Mean-Field Treatment of Magnetic Properties of Yittrium-Cobalt-5 Under Moderate Hydrostatic Stress

[摘要] We explore the use of particular variants of DFT + U and DFT + orbital polarization (OP) to calculate the electronic structure and magnetic properties of YCo5 under hydrostatic pressures up to 600 kbar. While the speci c DFT + U (with U= 0.75 eV) and DFT + OP schemes we employ produce magneto-crystalline anisotropy energies for YCo5 in good agreement with experiments performed in ambient conditions, our DFT + U results are shown to greatly overestimate the pressure at which a high-spin to low-spin (HS-LS) transition is known to occur. In contrast, our DFT + OP results predict the HS-LS transition to occur at the same stress as DFT, and in better agreement with experiment. This sensitivity suggests that care should be taken when attempting to model magnetic properties with self-interaction and/or correlation corrections to DFT for this and related materials, and highlights the usefulness of moderate pressure as an additional parameter to vary when discriminating between candidate theoretical schemes.

[发布日期] 2015-10-26

[学科分类] 凝聚态物理