2014/09/21 by Jian-Sheng Xia, Andrzej Ożarowski, Xia, Jian-Sheng +9
Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #FOS: Physical sciences #Magnetism in coordination complexes #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.1409.5971
openalex publication_date 2014/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
An S=1 antiferromagnetic polymeric chain, [Ni(HF2)(3-Clpy)4]BF4\n(py = pyridine), has previously been identified to have intrachain,\nnearest-neighbor antiferromagnetic interaction strength J/k\B =\n4.86 K and single-ion anisotropy (zero-field splitting) D/k\B =\n4.3 K, so the ratio D/J = 0.88 places this system close to the D/J \≈\n1 gapless critical point between the topologically distinct Haldane and\nLarge-D phases. The magnetization was studied over a range of temperatures,\n50 mK \≤ T \≤ 1 K, and magnetic fields, B \≤ 10 T, in an attempt to\nidentify a critical field, B\c, associated with the closing of the\nHaldane gap, and the present work places an upper bound of B\c \≤\n(35 \± 10) mT. At higher fields, the observed magnetic response is\nqualitatively similar to the "excess" signal observed by other workers at 0.5 K\nand below 3 T. The high-field (up to 14.5 T), multi-frequency (nomially 200 GHz\nto 425 GHz) ESR spectra at 3 K reveal several broad features considered to be\nassociated with the linear-chain sample.\n