CHARACTERIZATION OF THE GROWTH-PROCESS OF TB/FE MULTILAYERS BY ELECTRICAL-RESISTIVITY

Tb/Fe multilayers are obtained by vacuum evaporation on substrates kept at different temperatures (in the 90 to 420 K range). In order to characterize the structure of the terbium and iron layers, electrical resistivity measurements are performed during the deposition process. At low substrate temperature iron is first amorphous and then crystallizes at a critical thickness depending on the deposition temperature. At high substrate temperature, it forms an amorphous alloy with the rare-earth, then pure b.c.c. iron grows. Terbium shows a large resistivity due to the crystallinity of the layers. The results are consistent with Mossbauer spectroscopy and electron microscopy observations.