2007/05/31 by Meng Gao, Sen Zhou, Ziqiang Wang
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Chemistry #Condensed matter physics #Crystallography #Doping #Ferromagnetism #Lattice (music) #Magnetic and transport properties of perovskites and related materials #Magnetic moment #Magnetism #Materials science #Paramagnetism #Physics #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.76.180402
published as Phys. Rev. B 76, 180402(R) (2007) · revtex4 file, 5 pages, 3 figures, published version
openalex publication_date 2007/11/07 · arxiv created 2007/11/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the interplay between correlation, itinerant ferromagnetism, and local moment formation on the electron doped triangular lattice of sodium cobaltates NaxCoO2. We find that strong correlation renormalizes the Stoner criterion and stabilizes the paramagnetic state for x<xc\ensuremath≃0.67. For x>xc, ferromagnetic (FM) order emerges. The enhanced Na dopant potential fluctuations play a crucial role in the sodium-rich phases and lead to an inhomogeneous FM state, exhibiting nonmagnetic Co3+ patches, antiferromagnetic (AF) correlated regions, and FM clusters with AF domains. Hole doping the band insulator at x=1 leads to the formation of local moments near the Na vacancies and AF correlated magnetic clusters. We explain recent observations by neutron, \ensuremathμSR, and NMR experiments on the evolution of the magnetic properties in the sodium-rich phases.