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Experimental Verification of the Gapless Point in the $S$=1 Antiferromagnetic Bond Alternating Chain

M. Hagiwara·Y. Narumi·K. Kindo·M. Kohno·H. Nakano·R. Sato·M. Takahashi
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Abstract

Susceptibility and high field magnetization measurements have been performed on powder samples of an $S$=1 bond alternating chain compound [\{Ni(333-tet)($μ$-N$_3$)\}$_n$](ClO$_4$)$_n$ (333-tet=tetraamine N,N'-bis(3-aminopropyl)-1,3-propanediamine). As the temperature is decreased, the susceptibility exhibits a round maximum at around 120 K and decreases gradually down to 10 K, and then falls down rapidly with a logarithmic curvature which is behavior of the susceptibility of a gapless or a nearly gapless antiferromagnetic chain. Magnetization up to 50 T at 1.4 K shows no or a very small gap in this compound. We have carried out numerical calculations for the $S$=1 antiferromagnetic bond alternating chain with various alternating ratios $α$ and obtained a very good agreement between experiments and calculations for $α$=0.6. We verify experimentally that the gapless point exists around $α$=0.6.

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M. Hagiwara, Y. Narumi, K. Kindo, M. Kohno, H. Nakano, R. Sato, M. Takahashi. 1997-08-18. Experimental Verification of the Gapless Point in the $S$=1 Antiferromagnetic Bond Alternating Chain. https://doi.org/10.1103/physrevlett.80.1312

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