Energetics and local spin magnetic moment of single 3,4d impurities encapsulated in an icosahedral Au₁₂ cage [86]

The energetics and local spin magnetic moment of a single 3,4d impurity (Sc-Ni, Y-Pd) encapsulated in an icosahedral Au₁₂ cage have been studied theoretically by using a real-space first-principles cluster method with generalized gradient approximation for exchange-correlation functional. The relativistic effect is considered by scalar relativistic pseudopotentials. All doped clusters show unexpected large relative binding energies compared with icosahedral Au₁₃ cluster. The smallest and the largest values appear at Pd and Zr, 2.186 and 7.791 eV per cluster, respectively, indicating doping could stabilize the icosahedral Au₁₂ cage and promote the formation of a new binary alloy cluster. Comparatively large magnetic moments are observed for 3d elements Cr, Mn, Fe, Co, and Ni (2.265, 3.512, 3.064, 1.947, and 0.943 μ_B), and 4d elements Tc, Ru, and Rh (0.758, 1.137, and 0.893 μ_B). The density of states and the relativistic effects on electronic structure are discussed.