Magnetism and the Stoner Exchange Parameter of fcc Palladium

Magnetism and the Stoner Exchange Parameter of fcc Palladium

We performed first-principles density functional calculations on the magnetism of fcc palladium by employing the highly precise full-potential linearized augmented plane-wave method. The local spin density approximation (LSDA) was employed to describe the exchange-correlation potential. In this study, the magnetic behavior of fcc bulk Pd was calculated as a function of the lattice constant. The lattice constant at magnetic onset was carefully determined to be between 3.91 and 3.94 A, which is just a little bit (less than 1.5%) expanded compared to the lattice constant (3.862A) at equilibrium. From the calculated density of states at the Fermi level for the lattice constant at magnetic onset, we determined the Stoner parameter, I, to be 0.40. On the other hand, the calculation with a general gradient approximation (GGA) for the exchange-correlation potential gave a wrong result that a ferromagnetic state was more stable than a paramagnetic one at its equilibrium lattice constant (3.956 A). The present study proves that LSDA might give better results than GGA for a relatively delocalized electron system such as a 4d transition metal.

We performed first-principles density functional calculations on the magnetism of fcc palladium by employing the highly precise full-potential linearized augmented plane-wave method. The local spin density approximation (LSDA) was employed to describe the exchange-correlation potential. In this study, the magnetic behavior of fcc bulk Pd was calculated as a function of the lattice constant. The lattice constant at magnetic onset was carefully determined to be between 3.91 and 3.94 A, which is just a little bit (less than 1.5%) expanded compared to the lattice constant (3.862A) at equilibrium. From the calculated density of states at the Fermi level for the lattice constant at magnetic onset, we determined the Stoner parameter, I, to be 0.40. On the other hand, the calculation with a general gradient approximation (GGA) for the exchange-correlation potential gave a wrong result that a ferromagnetic state was more stable than a paramagnetic one at its equilibrium lattice constant (3.956 A). The present study proves that LSDA might give better results than GGA for a relatively delocalized electron system such as a 4d transition metal.