Electronic structure, magnetic properties, and exchange splitting of gadolinium intermetallics

Ensign, Brian; Choudhary, Renu; Ucar, Huseyin; Paudyal, Durga

Electronic structure, magnetic properties, and exchange splitting of gadolinium intermetallics

File

IS_J_10204.pdf (569.77 KB)

Date

2020-09-01

Authors

Ensign, Brian

Choudhary, Renu

Ucar, Huseyin

Paudyal, Durga

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.

Organizational Unit

Materials Science and Engineering

Materials engineers create new materials and improve existing materials. Everything is limited by the materials that are used to produce it. Materials engineers understand the relationship between the properties of a material and its internal structure — from the macro level down to the atomic level. The better the materials, the better the end result — it’s as simple as that.

Department

Ames National LaboratoryMaterials Science and Engineering

Abstract

We report here the electronic structure calculations of the magnetic moment, magneto-crystalline anisotropy energy (MAE), and density of states (DOS) of Gd-metal, GdAl2, GdAl3, GdCo2, GdCo3, and GdCo5. From the DOS, the exchange splitting energy is derived to map ferrimagnetic to paramagnetic phase transition (Curie temperature, TC). The employed theoretical method here is based on advanced density functional theory, specifically the linearized augmented plane wave method (LAPW) within the local spin density approximation (LSDA), including spin–orbit coupling (SOC) and Hubbard model parameter (U). DOS analysis of both Gd-Al and Gd-Co systems reveals a strong correlation between exchange splitting energy and TC. The Gd-Co system exhibits an enormous exchange splitting energy among Co-3d electrons, vastly overwhelming the vanishing Gd 5d exchange splitting. These findings suggest that exchange splitting of Co-3d electrons plays a key role in the ground state magnetism and magnetic transition temperatures in these materials.