2005/05/31 by G. Lang, Guillaume Lang, Julien Bobroff +5 · 6 citations
Materials Science · Physics and Astronomy · #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.72.094404
published as Phys. Rev. B 72, 094404 (2005) · 7 pages, LaTeX ; v2: corrected typos, minor additions
openalex publication_date 2005/09/08 · arxiv created 2005/09/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Macroscopic magnetization, muon spin rotation (\ensuremathμSR), and NMR measurements were carried out to study magnetism in the Na1CoO2 cobaltate. Using superconducting quantum interference device measurements, Na1CoO2 is shown to have a bulk magnetic susceptibility much lower and flatter than that of NaxCoO2 with x=0.7\text\ensuremath-0.9. In fact, \ensuremathμSR yields a signal of mostly nonmagnetic origin, which is attributed to the x=1 phase. The intrinsic cobalt spin susceptibility corresponding to this x=1 phase is measured using 23Na NMR. It is indeed found to be almost zero, in agreement with a low-spin 3+ charge state of all cobalt atoms. This single state of Co ions in CoO2 planes is confirmed by 59Co NMR, whose determination of cobalt shift and quadrupolar parameters allows us to give a reference value of the Co3+ orbital shift in cobaltates.