Date of this Version
JOURNAL OF APPLIED PHYSICS 109, 07E322 (2011); doi:10.1063/1.3559505
Ab initio calculations of the biaxial anisotropy of infinite Pd zigzag chains are presented. The simulations were performed with the Vienna Ab-Initio Simulation Package, using a tetragonal unit cell with a supercell approach where the atoms are repeated along the z-direction. The anisotropy is determined from the energies along the three principal directions , , and . The second-order anisotropy constants K1 and K'1 were extracted by fitting the calculated energy values to the phenomenological energy. The easiest magnetization direction is along the wire axis, whereas the hardest direction is perpendicular to the plane of the wire. The calculated anisotropy constants K1 and K'1 are 5.5 MJ/m3 and -13.9 MJ/m3, respectively These anisotropies are large, but they are smaller than those of linear chains, because the zigzag shape leads to a quenched orbital moment.