Modification of magnetoresistance and magnetic properties of Ni thin films by adding Dy interlayer S I Vorobiov, T M Shabelnyk, O V Shutylieva, I M Pazukha, A M Chornous Materials Research Express, 2018 The paper reports the influence of dysprosium (Dy) interlayer addition on structure, magnetoresistance and magnetic properties of nickel (Ni) thin films. Trilayer film systems Ni/Dy/Ni have been prepared by alternate electron-beam evaporation. It is demonstrated that all as-prepared and annealed Ni thin films have face-centered cubic structure. The composition of the samples after addition of the Dy interlayer corresponds to the combination of face-centered cubic (Ni) and hexagonal close-packed (Dy) structures. The structure of Ni/Dy/Ni film systems changes from amorphous to polycrystalline when Dy interlayer thickness (tDy) is more than 15 nm. The value of magnetoresistance increases with the adding the Dy interlayer in both longitudinal and transverse geometries, meanwhile the anisotropic character of magnetoresistance field dependences retained. The saturation and reversal magnetizations are reduced with the increasing of the Dy thickness interlayer, while the coercivity takes the minimum value at tDy = 15 nm. The following increasing of tDy leads to increasing of coercivity near to three times. This result indicates the influence of the crystal structure on the magnetic properties of Ni thin films at adding Dy interlayer.
Effect of separated layer thickness on magnetoresistance and magnetic properties of Co/Dy/Co and Ni/Dy/Ni film systems T. M. Shabelnyk, O. V. Shutylieva, S. I. Vorobiov, I. M. Pazukha, A. M. Chornous International Journal of Modern Physics B, 2018 Co(5 nm)/Dy(t[Formula: see text])/Co(20 nm)/S and Ni(5 nm)/Dy(t[Formula: see text])/Ni(20 nm)/S trilayer films are prepared by electron-beam sputtering to investigate the influence of dysprosium layer thickness (t[Formula: see text]) and thermal annealing on the crystal structure, magnetoresistance (MR) and magnetic properties of thin films. The thickness of Dy layer changed in the range from 1 nm to 20 nm. The samples annealed for 20 min at 700 K. Electron diffraction patterns reveal that the as-deposited and annealed systems Co/Dy/Co and Ni/Dy/Ni had fcc-Co + hcp-Dy and fcc-Ni + hcp-Dy phase state, respectively. It is also shown that at the t[Formula: see text] = 15 nm the transition from amorphous to crystalline structures of Dy layer is observed. An increase in the Dy layer thickness results in changes in the MR and magnetic properties of the trilayer systems. It is shown that MR is most thermally stable against annealing to 700 K at t[Formula: see text] = 15 nm for Co/Dy/Co as well as for Ni/Dy/Ni. For t[Formula: see text] = 15 nm the, value of MR for both system increases by two times compared to those of pure ferromagnetic (FM) samples. The coercivity (B[Formula: see text]), remanent (M[Formula: see text]) and saturation (M[Formula: see text]) magnetization of the in-plain magnetization hysteresis loops are related to the Dy layer thickness too. The coercivity depends on the FM materials type and diffusion processes at the layer boundary. Accordingly, M[Formula: see text] and M[Formula: see text] are reduced with t[Formula: see text] increasing before and after annealing for both trilayer systems.
Sensitive element of the magnetic field sensor based on three-layer film system Co/X/Co (X = Dy, Gd) S. I. Vorobiov, O. V. Shutylieva, I. M. Pazukha, A. M. Chornous Technical Physics, 2014 We report on the results of investigation of magnetoresistive properties of Co/Dy/Co and Co/Gd/Co film systems that can be used as the sensitive element of a magnetic field sensor. It is shown that various fields of application can be chosen depending on the magnetic characteristics.
The phase composition and magnetic properties of film systems based on Fe(Co) and Gd(Dy) Journal of Nano and Electronic Physics, 2014
Magnetoresistive properties of thin film systems based on Fe - Gd and Co - Gd Journal of Nano and Electronic Physics, 2012
