An alternate model for magnetization plateaus in the molecular magnet $V_{15}$

Rudra, Indranil and Ramasesha, S and Sen, Diptiman (2001) An alternate model for magnetization plateaus in the molecular magnet $V_{15}$. In: Journal of Physics:Condensed Matter, 13 (50). 11717 -11725.

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Abstract

Starting from an antiferromagnetic Heisenberg Hamiltonian for the 15 spin-1/2 ions in $V_{15}$, we construct an effective spin Hamiltonian involving eight low-lying states (spin-1/2 and spin-3/2) coupled to a phonon bath. We numerically solve the time-dependent Schrodinger equation of this system, and obtain the magnetization as a function of temperature in a time-dependent magnetic field. The magnetization exhibits unusual patterns of hysteresis and plateaus as the field sweep rate and temperature are varied. The observed plateaus are not due to quantum tunnelling but are a result of thermal averaging. Our results are in good agreement with recent experimental observations.

Item Type:	Journal Article
Publication:	Journal of Physics:Condensed Matter
Publisher:	Institute of Physics
Additional Information:	Copyright of this article belongs to Institute of physics.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Physical & Mathematical Sciences > Centre for Theoretical Studies (Ceased to exist at the end of 2003)
Date Deposited:	16 Mar 2007
Last Modified:	19 Sep 2010 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/10416

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