title: The linear and non-linear magnetic response of a tri-uranium single molecule magnet.
abstract: We report here low temperature magnetization isotherms for the single molecule magnet, (UO2-L)3. By analyzing the low temperature magnetization in terms of M  =  χ1B  +  χ3B3we extract the linear susceptibility χ1and the leading order nonlinear susceptibility χ3. We find that χ1exhibits a peak at a temperature of T1=  10.4 K with χ3also exhibiting a peak but at a reduced temperature T3=  5 K. At the lowest temperatures the isotherms exhibit a critical field Bc=  11.5 T marked by a clear point of inflection. A minimal Hamiltonian employing S  =  1 (pseudo) spins with only a single energy scale (successfully used to model the behavior of bulk f-electron metamagnets) is shown to provide a good description of the observed linear scaling between T1, T3and Bc. We further show that a Heisenberg Hamiltonian previously employed by Carretta et al (2013 J. Phys.: Condens. Matter 25 486001) to model this single molecule magnet gives formulas for the angle averaged susceptibilities (in the Ising limit) very similar to those of the minimal model.
authors.affiliation: Department of Physics, University of Virginia, Charlottesville, VA 22901, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Shivaram
authors.forename: E
authors.initials: E
authors.lastname: Colineau
authors.forename: J
authors.initials: J
authors.lastname: Griveau
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: V
authors.initials: V
authors.lastname: Celli