Solid-state synthesis, dewetting, and magnetic and structural characterization of interfacial FexSn1-x layers in Sn/Fe(001) thin films

The phase formation sequences in 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers during thin-film solid-state reactions up to 800°C were investigated using X-ray diffraction, the torque method, and scanning electron microscopy. In both samples, FeSn₂, FeSn, α-Fe_1−xSn_x, Fe₅Sn₃, α-Fe, and β-Sn were sequentially formed at the initiation temperatures T_inⁱ ~ 150°C, ~ 300°C, ~ 550°C, ~ 600°C, and ~ 700°C, respectively. Low-temperature transformations were predicted at temperatures T_K¹ ~ 150°C and T_K² ~ 300°C, which are absent in the phase equilibrium diagram of the Fe–Sn system. Solid-state dewetting of the 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers started at temperatures above 550°C. Overall, this work sheds new light on general chemical mechanisms governing the synthesis of intermetallic phases in Sn/Fe(001) thin films, the phase transformations, and the evolution of the dewetting process of Fe_xSn_1−x films.

• DOIhttps://doi.org/10.1557/s43578-021-00312-4