Thickness Effect on Interdiffusion of Fe/Pt Multilayers

• Published in: Metals and materials international 2008-02, Vol.14 (1), p.111
• Main Authors: Dan Phuong Nguyen, Chan Woo Park, Young Min Lee, Kee Sam Shin, Hee Kyu Choi, Woo Hyun Chung, Chan Gyu Lee
• Format: Article
• Language: Korean
• Subjects: activation energy; Fe/Pt; interdiffusion; interdiffusion coefficient; multilayer thin film
• ISSN: 1598-9623; 2005-4149

The effect of thickness on interdiffusion in Fe/Pt multilayer thin films was studied using rapid thermal annealing. [Fe(1 nm)/Pt(1 nm)]20 and [Fe(3 nm)/Pt(3 nm)]10 multilayers were prepared via DC magnetron sputtering and subsequently annealed at temperatures of 523 K to 603 K 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 in the range of 523 K to 603 K can be described by D(t) = 3.42 × 10-15 exp(-0.83 eV/kBT) (m2/s) for [Fe(1 nm)/Pt(1 nm)]20 and D(T) = 7.85 × 10-16 exp(-0.62 eV/kBT) (m2/s) for [Fe(3 nm)/Pt(3 nm)]10. The activation energy Q = 0.83 eV for [Fe(1 nm)/Pt(1 nm)]20 is higher than that of Q = 0.62 eV for [Fe(3 nm)/Pt(3 nm)]10. This phenomenon suggests that the atoms in the thicker film can move more easily in the interface and the lattice, which results in lower activation energy and higher diffusivity.