Unique electronic structure and the shape-change effect of stage-I graphite intercalation compounds with Thorium, Uranium and Plutonium

Abstract

GICs doped with elements containing d and f orbitals have been studied rarely. We control the distribution and density of intercalated actinide metals (Th, U and Pu), and consider the effect of changing the distance of two adjacent carbon layers on the electronic structure so as to infer the physical properties of such materials under high pressure or high temperature - which is of great significance in fundamental research. According to band schemas, those GICs are all metallic. The projected density of states (PDOS) indicates that the metal atoms first undergo hybridization of its s, p, d, and f orbitals, and then bond with the carbon's pz orbitals of the nearest-neighbor octagons. The electron orbital spin up of C and Th is symmetrical with spin down, so there is no electron spin polarization. However, the s, p, d, and f orbitals of U and Pu all exhibit electron spin polarization, which leads to the magnetic properties of the material and make the p orbits of C appear spin polarization around Fermi level. In addition, these three selected elements are the most commonly used raw materials in nuclear fission, so such GICs are expected to become novel nuclear energy storage materials.