Heisenberg spin triangles in {V6}-type magnetic molecules: Experiment and theory

Thumbnail Image
Date
2002-08-05
Authors
Luban, Marshall
Borsa, Ferdinando
Bud'ko, Sergey
Jun, Suckjoon
Jung, Jae Kap
Kögerler, Paul
Mentrup, Detlef
Müller, Achim
Modler, Robert
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Canfield, Paul
Distinguished Professor
Research Projects
Organizational Units
Organizational Unit
Ames National Laboratory

Ames National Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, Iowa.

For more than 70 years, the Ames National Laboratory has successfully partnered with Iowa State University, and is unique among the 17 DOE laboratories in that it is physically located on the campus of a major research university. Many of the scientists and administrators at the Laboratory also hold faculty positions at the University and the Laboratory has access to both undergraduate and graduate student talent.

Journal Issue
Is Version Of
Versions
Series
Abstract

We report the results of systematic experimental and theoretical studies of two closely related species of magnetic molecules of the type {V6}, where each molecule includes a pair of triangles of exchange-coupled vanadyl (VO2+,spin s=1/2) ions. The experimental studies include the temperature dependence of the low-field susceptibility from room temperature down to 2 K, the dependence of the magnetization on magnetic field up to 60 T for several low temperatures, the temperature dependence of the magnetic contribution to the specific heat, and the 1H and 23Nanuclear magnetic resonance spin-lattice relaxation rates 1/T1. This body of experimental data is accurately reproduced for both compounds by a Heisenberg model for two identical uncoupled triangles of spins; in each triangle, the spins interact via isotropic antiferromagnetic exchange, where two of the three V-V interactions have exchange constants that are equal and an order of magnitude larger than the third; the ground-state eigenfunction has total spin quantum number S=1/2 for magnetic fields below a predicted critical field Hc≈74T and S=3/2 for fields above Hc.

Comments

This article is from Physical Review B 66 (2002): 054407, doi:10.1103/PhysRevB.66.054407. Posted with permission.

Description
Keywords
Citation
DOI
Subject Categories
Copyright
Thu Jan 01 00:00:00 UTC 2009
Collections