2005/09/14 by Zachary M. Helms, Zachary Helms, Prasenjit Sen +5
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties of Alloys #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/0509363
5 pages, 3 figures
arxiv created 2005/09/14 · openalex publication_date 2005/09/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Electronic structure calculations using quantum Monte Carlo (QMC) methods conclusively show that pure CaB6 is a narrow-gap semiconductor with an X-point gap ∼ 1.3 eV. This should put to rest controversies as to whether the compound is a semimetal or a semiconductor, as also theories suggesting it to be an excitonic insulator. Our extensive Hartree-Fock (HF) and density functional theory (DFT) calculations support the view that the hexaboride ferromagnetism can be induced by contamination with magnetic element atoms like Fe and that presence of La is not essential for this. La impurity, however, gives rise to a metallic state with a small electron-like Fermi surface as seen in ARPES experiments.