Structure and Magnetic Properties of Ni/Ti Multilayers

B. Szymański, F. Stobiecki Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17/19, 60-179 Poznań, Poland T. Otto and K. Röll University of Kassel, FB Physik, Kassel, Germany

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We report a study of structure and magnetic properties of Ni/Ti multilayers with different modulation wavelength, 10 nm ≤ λ ≤ 40 nm, and constant sublayers thickness ratio dNi/dTi=1. Specimens were characterized with X-ray diffraction, vibrating sample magnetometer and torque meter in as-deposited state and in successive stages of isothermal annealing at 423 K. Hysteresis curves of as-deposited samples revealed the typical feature of ferromagnetic films with predominant shape anisotropy. During annealing very pronounced changes in the hysteresis loops were observed. An analysis of the loops indicates the occurrence of distinct changes in magnetic anisotropy of Ni sublayers: their effective shape anisotropy is drastically reduced due to a development of the perpendicular anisotropy and/or a modification of the microstructure. The effect can possibly be applied to achieve desirable variation of perpendicular anisotropy in multilayers which consist of Ni sublayers.

DOI: 10.12693/APhysPolA.91.233 PACS numbers: 75.50.Kj, 75.70.-i