Magnetocrystalline anisotropy in ${\mathrm{UMn}}_{2}{\mathrm{Ge}}_{2}$ and related Mn-based actinide ferromagnets

Magnetocrystalline anisotropy in ${UMn}_{2} {Ge}_{2}$ and related Mn-based actinide ferromagnets

David S. Parker, Nirmal Ghimire, John Singleton, J. D. Thompson, Eric D. Bauer, Ryan Baumbach, David Mandrus, Ling Li, and David J. Singh

Phys. Rev. B 91, 174401 – Published 4 May 2015

Abstract

We present magnetization isotherms in pulsed magnetic fields up to 62 T, supported by first-principles calculations, demonstrating a huge uniaxial magnetocrystalline anisotropy energy—approximately 20 $MJ / m^{3}$ —in ${UMn}_{2} {Ge}_{2}$ . This large anisotropy results from the extremely strong spin-orbit coupling affecting the uranium $5 f$ electrons, which in the calculations exhibit a substantial orbital moment exceeding $2 μ_{B}$ . We also find from theoretical calculations that a number of isostructural Mn actinide compounds are expected to have similarly large anisotropy.

Received 28 January 2015
Revised 15 April 2015

DOI:https://doi.org/10.1103/PhysRevB.91.174401

Authors & Affiliations

David S. Parker

Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6056, USA

Nirmal Ghimire, John Singleton, J. D. Thompson, and Eric D. Bauer

Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

Ryan Baumbach

National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA

David Mandrus

Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA and Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA

Ling Li