Growth, structure and magnetic properties of Co ultrathin films on Cu(111) by pulsed laser deposition

Abstract

Deposition of Co on Cu(111) substrate by laser ablation changes the morphology, structure and magnetic properties of Co ultrathin films. The pulsed laser deposition method induces a good layer-by-layer growth of Co films and delays the face centred cubic to hexagonal close packed structural phase transition in the films. As a result, the pulsed laser deposited films retain an in-plane easy axis of magnetization at all thicknesses investigated (0-15 monolayers Co) while the thermally deposited films also exhibit a hysteresis loop in the perpendicular direction as soon as the hexagonal close packed structure is dominant in the film. In addition, the suppression of hexagonal close packed stacking in the pulsed laser deposited films leads to a complete antiferromagnetic coupling in Co/Cu/Co/Cu(111) trilayers for both in-plane and out-of-plane magnetization directions.