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Experimental Evidence of a Haldane Gap in an S = 2 Quasi-linear Chain Antiferromagnet

G. E. Granroth·M. W. Meisel·M. Chaparala·Th. Jolicoeur·B. H. Ward·D. R. Talham
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Abstract

The magnetic susceptibility of the $S = 2$ quasi-linear chain Heisenberg antiferromagnet (2,$2'$-bipyridine)trichloromanganese(III), MnCl_{3}(bipy), has been measured from 1.8 to 300 K with the magnetic field, H, parallel and perpendicular to the chains. The analyzed data yield $g\approx 2$ and $J\approx 35$ K. The magnetization, M, has been studied at 30 mK and 1.4 K in H up to 16 T. No evidence of long-range order is observed. Depending on crystal orientation, $M\approx 0$ at 30 mK until a critical field is achieved ($H_{c\|} = 1.2\pm 0.2 T$ and $H_{c\bot} = 1.8\pm 0.2 T), where M increases continuously as H is increased. These results are interpreted as evidence of a Haldane gap.

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G. E. Granroth, M. W. Meisel, M. Chaparala, Th. Jolicoeur, B. H. Ward, D. R. Talham. 1997-07-11. Experimental Evidence of a Haldane Gap in an S = 2 Quasi-linear Chain Antiferromagnet. https://doi.org/10.1103/physrevlett.77.1616

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