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MA: Fachverband Magnetismus
MA 62: Disodered Magnetic Materials
MA 62.8: Vortrag
Freitag, 20. März 2020, 11:15–11:30, HSZ 401
Uniform Heisenberg spin chain in sarrabusite Pb5Cu(SeO3)4Cl4 — •Ekaterina Kozlyakova, Artem Moskin, Alisher Murtazoev, Peter Berdonosov, and Alexander Vasiliev — Lomonosov MSU, Moscow, Russia
One-dimensional antiferromagnets have exotic disordered ground states. The uniform half-integer spin chain does not present a gap in the triplet excitation spectrum and it is disordered in an isotropic Heisenberg case. In any real material an ideal S = 1/2 chain cannot exist because an infinitesimal interchain coupling would give rise to long-range magnetic order at finite temperatures. [1, 2] In this work we present novel uniform spin chain compound Pb5Cu(SeO3)4Cl4 that demonstrates no long-range magnetic ordering up to 2 K. Its magnetic susceptibility agrees well with the Bonner-Fisher’s model with J = 129K for Heisenberg AFM S = 1/2 spin chain [3]. Thus, Pb5Cu(SeO3)4Cl4 is one of the very few uniform spin chains where no long-range magnetic ordering or any singlet formation were observed above 2 K, while J is of the order of 100 K.
[1] E. Lieb, et al. Annals Phys. 16, 407-466 (1961).
[2] D.C. Johnston, et al. Phys. Rev. B 61, 9558-9606 (2000).
[3] J.C. Bonner & M.E. Fisher. Phys. Rev. A 135, 640-658 (1964).