Magnetic properties of TbPc2-type single-molecule magnets from first principles quantum-chemical calculations
Ryan Pederson,1 Aleksander Wysocki,1 Nicholas Mayhall,2 and Kyungwha Park1
1Department of Physics, Virginia Tech,
Blacksburg, Virginia 24061, United States
2Department of Chemistry, Virginia Tech,
Blacksburg, Virginia 24061, United States
Recent experiments showed that lanthanide-based single-molecule magnets (SMMs) have exceptionally large magnetic anisotropy and that they can be used for experimental realization of quantum information applications, with a judicious choice of chemical environment. Here, we investigate how different chemical factors influence electronic structure and magnetic properties of TbPc2-type SMMs using relativistic multiconfigurational ab initio calculations. The low-energy electronic spectra of the SMMs are evaluated and an effective pseudospin Hamiltonian is constructed. We examine how oxidation state, ligand type and details of molecular geometry affect several important energy scales such as tunnel splitting, exchange coupling between the Tb moment and the ligand spin, zero-field splitting, and magnetic anisotropy barrier. Based on these results, we discuss mechanisms of magnetization relaxation in TbPc2-type SMMs.
Funded by the Department of Energy Basic Energy Sciences grant No DE-SC0018326. Computational support by Virginia Tech ARC.