The Linear and Non-linear Magnetic Response of a Tri-Uranium Single Molecule Magnet

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  =  χ 1 B  +  χ 3 B 3 we extract the linear susceptibility χ 1 and the leading order nonlinear susceptibility χ 3. We find that χ 1 exhibits a peak at a temperature of T 1  =  10.4 K with χ 3 also exhibiting a peak but at a reduced temperature T 3  =  5 K. At the lowest temperatures the isotherms exhibit a critical field B c  =  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 T 1, T 3 and B c. 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.

SHIVARAM Bellave;  COLINEAU Eric;  GRIVEAU Jean-Christophe;  KUMAR Pradeep;  CELLI Vittorio; 

2017-12-04

IOP PUBLISHING LTD

JRC106683

0953-8984,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC106683,   

10.1088/1361-648X/aa553e,