2007/04/09 by Daisuke Yoshizumi, Yuji Muraoka, Yoshihiko Okamoto +5
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #Conduction band #Copper-based nanomaterials and applications #Crystallite #Density of states #Electron #Electronic band structure #Fermi Gamma-ray Space Telescope #Fermi level #Heusler alloys: electronic and magnetic properties #Paramagnetism #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.76.063705
published as J. Phys. Soc. Jpn. 76 (2007) 063705 · 4 pages, 5 figures, submitted to J. Phys. Soc. Jpn
arxiv created 2007/04/09 · openalex publication_date 2007/06/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Electronic properties of the sodium cobaltate NaxCoO2 are systematically studied through a precise control of band filling. Resistivity, magnetic susceptibility and specific heat measurements are carried out on a series of high-quality polycrystalline samples prepared at 200 C with Na content in a wide range of 0.35 =< x =< 0.70. It is found that dramatic changes in electronic properties take place at a critical Na concentration x* that lies between 0.58 and 0.59, which separates a Pauli paramagnetic and a Curie-Weiss metals. It is suggested that at x* the Fermi level touches the bottom of the a1g band at the gamma point, leading to a crucial change in the density of states across x* and the emergence of a small electron pocket around the gamma point for x > x*.