The effect of thickness on interdiffusion in Fe/Pt multilayer thin films was studied using rapid thermal annealing. [Fe(1nm)/Pt(1nm)]20 and [Fe(3nm)/Pt(3nm)]10 multilayers were prepared via DC magnetron sputtering and subsequently annealed at 523 to 603K in an argon atmosphere in an infrared lamp furnace for a very short time. X-ray diffraction yielded the interdiffusion coefficients from the slopes of the satellite peak versus annealing time. The temperature dependence of interdiffusion at 523 to 603K could be described by:

D(m2/s) = 3.42 x 10−15 exp[-0.83(eV)/kT]

for [Fe(1nm)/Pt(1nm)]20 and:

D(m2/s) = 7.85 x 10−16 exp[-0.62(eV)/kT]

for [Fe(3nm)/Pt(3nm)]10. The fact that the activation energy for [Fe(1nm)/Pt(1nm)]20 was higher than that for [Fe(3nm)/Pt(3nm)]10 suggested that the atoms in the thicker film could move more easily in the interface and the lattice; which resulted in a lower activation energy and higher diffusivity.

Thickness Effect on Interdiffusion of Fe/Pt Multilayers. D.P.Nguyen, C.W.Park, Y.M.Lee, K.Shin, H.K.Choi, W.H.Chung, C.G.Lee: Metals and Materials International, 2008, 14[1], 111-5