Quantum well states and interface quality in Cu/Co(100)/Cu(100) system

Quantum well states are observed in Cu films grown on magnetic fcc-Co(100), using high-resolution photoemission. fcc-Co(100) films were obtained by room temperature epitaxy on a Cu(100) substrate. Cu films of different thickness were grown stepwise on top of the fcc-Co(100) layer following two different preparation methods. In the first one, the first deposition step was performed at 100 K, while the rest of the deposition took place at room temperature. In the second method, the whole process was carried out at room temperature. The initial deposition at low temperature produced an abrupt, non-reacted Cu/Co interface, whereas the Co/Cu interface obtained in the second case was of less quality. High-quality quantum well states were observed only in the low-temperature deposition case, revealing the importance of an abrupt interface in the confinement of the quantum well states.