Eur. Phys. J. B 26, 41-50 (2002)
https://doi.org/10.1140/epjb/e20020064

Solid-state reaction in Ti/Ni multilayers studied by magneto-optical and optical spectroscopies, and X-ray diffraction

¹ Department of Physics, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul, 133-791, Korea
² Department of Physics, Sunmoon University, 100 Galsan-Ri, Tangjeong-Myeon, Asan, Choongnam, 336-840, Korea
³ Institute of Metal Physics, National Academy of Sciences of Ukraine, 36 Vernadsky str., Kiev-142, Ukraine
⁴ Institute of Molecular Physics, Polish Academy of Sciences, 17 Smoluchowskiego str., 60-179 Poznań, Poland

Corresponding author: ^a yplee@hanyang.ac.kr

Received: 2 May 2001
Revised: 21 November 2001
Published online: 15 March 2002

Abstract

Comparative study of the solid-state reaction (SSR) in a series of Ti/Ni multilayered films (MLF) with a bilayer period of 0.65–22.2 nm and a constant Ti to Ni sublayer thickness ratio has been performed by using the experimental and computer-simulated magneto-optical (MO) and optical spectroscopies as well as X-ray diffraction (XRD). It was shown that alloyed-like regions in an amorphous structure is spontaneously formed near the interfaces between pure elements during the film deposition. The thickness of this region was estimated as 2–3.8 nm on the basis of the MO and optical studies. The SSR in the Ti/Ni MLF caused by an annealing at 580 K for 60 min increases the thickness of these interfacial amorphous regions. It was shown that SSR takes place mainly in the Ti/Ni MLF with relatively “thick” sublayers. The existence of a threshold nominal Ni-sublayer thickness for observing the equatorial Kerr effect of about 3.0 and 4.5 nm for the as-deposited and annealed Ti/Ni MLF, respectively, is explained by formation of the nonmagnetic alloyed regions between pure components during the film deposition as a result of the SSR. For the case of Ti/Ni MLF, the MO and optical approaches turn out to be more sensitive in determining the thickness of the reacted zone, while XRD is more useful for the structural analysis. It was also shown that the very thin nonreacted Ni sublayers have different MO properties (and hence electronic structure) from the bulk.