Recycling of Metal-Organic Ru Precursor and the Influence of Organic Impurities on the Surface Morphology of Ruthenium Films

Abstract

We present a technique for building itinerant electron states as approximate ground states to the spin half Anderson lattice Hamiltonian. We choose one fermionic state per site from amongst the two initial states, in the most general mathematical manner. Restricting the application of the Hamiltonian to states where only this special state is non-empty, we minimise the restricted energy in the Hartree-Fock approximation. Treating the initial choice of the relevant fermion as a variable, we then minimise the Hartree-Fock energy over this choice. The resulting energy is an upper bound on the ground state energy because the variational principle underpins our technique. Since we are forcing an itinerant solution onto the problem, this technique fails when the solution involves localised electrons behaving as spins together with non-interacting electrons. There are however large regions of parameter space where the energy found is less than the best localised solutions. We treat on-site hybridisation, nearest-neighbour hybridisation and Coulomb repulsion between the two types of electron with equal ease. Finally we consider speculative applications to the u-Ce to 7-Ce phase transition and a more reasonable application to the magnetic phase transitions in CeNi,Ptl-, and CeNi,Pdl-, and the similar systems CeSiz-, and CeSi2-,Ge,y.