Eur. Phys. J. B 32, 43-47 (2003)
https://doi.org/10.1140/epjb/e2003-00072-0

Magnetic susceptibility in quasi one-dimensional Ba₂V₃O₉: chain segmentation versus the staggered field effect

¹ Max Planck Institute for the Chemical Physics of Solids, Nöthnitzer Strasse 40, 01187 Dresden, Germany
² Joint Institute for Nuclear Research, Dubna, Russia
³ Max Planck Institute for the Physics of Complex Systems, Dresden, Germany

Corresponding author: ^a bs@cpfs.mpg.de

Received: 19 December 2002
Revised: 29 January 2003
Published online: 14 March 2003

Abstract

A pronounced Curie-like upturn of the magnetic susceptibility of the quasi one-dimensional spin chain compound Ba₂V₃O₉ has been found recently [CITE]. Frequently this is taken as a signature for a staggered field mechanism due to the presence of g-factor anisotropy and Dzyaloshinskii-Moriya interaction. We calculate this contribution within a realistic structure of vanadium 3d- and oxygen 2p-orbitals and conclude that this mechanism is far too small to explain experimental results. We propose that the Curie term is rather due to a segmentation of spin chains caused by broken magnetic bonds which leads to uncompensated spins of segments with odd numbers of spins. Using the finite-temperature Lanczos method we calculate their effective moment and show that of broken magnetic bonds is sufficient to reproduce the anomalous low-T behavior of in Ba₂V₃O₉.