Dynamic in situ optical and magneto-optical monitoring of the growth of Co/Au multilayers

In situ ellipsometry and Ken polarimetry have been used to follow, continuo usly, the evolution of the optical and magneto-optical properties of multip le layers of Co (5 Angstrom) and Au (37.5 Angstrom) during their deposition . A particular feature of the results shows marked oscillations of the magn eto-optic polar Kerr effect, with a period of about 16 Al during the deposi tion of each Au layer. The appearance of oscillations occurs in both Kerr e llipticity and rotation in a way that depends upon underlying buffer layer thickness and the number of bilayer periods in the multilayer stack. Magnet o-optical oscillations have been reported previously in Co/Au and Fe/Au sys tems and have been interpreted as being a consequence of magneto-optic tran sitions associated with quantum-well states in the noble-metal Layer. The c omprehensive optical and magneto-optical measurements reported here allow i ntrinsic material properties to be determined for developing ultrathin laye rs. These facilitate a better understanding of the observed magneto-optical signals that result from such structures and also provide a means of predi cting such signals for any optical system.