1995/08/09 by Takashi Tonegawa, Makoto Kaburagi
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetism in coordination complexes #Physics of Superconductivity and Magnetism #cond-mat
paper · pdf · doi:10.1143/jpsj.64.3956
18 pages, plain TeX with 4 tables(gzipped and uuencoded), 9 figures available upon request from [email protected], to be published in J. Phys. Soc. Jpn., Vol.64, No.10 (Oct. 1995)
arxiv created 1995/08/09 · openalex publication_date 1995/10/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Low-lying excited states as well as the ground state of the spin-1 antiferromagnetic Heisenberg chain with a spin-1/2 impurity are studied by means of a method of numerical diagonalization. The isotropic nearest-neighbor exchange coupling plus the uniaxial single-ion-type anisotropy energy is assumed for the host-system Hamiltonian. The energy differences between the ground state and the low-lying excited states, which appear in the Haldane gap, are estimated in the thermodynamic limit. The results are used to analyze the electron-spin-resonance experimental data on Ni(C2H8N2)2NO2(ClO4), abbreviated NENP, containing a small amount of spin-1/2 Cu2+ impurities. It is found that in this system, the impurity-host (Cu2+-Ni2+) coupling is ferromagnetic and its magnitude is about 5 % of the magnitude of the host-host (Ni2+-Ni2+) coupling.