Magnetic and magnetotransport study of Si/Ni multilayers correlated with structural and microstructural properties

• Published in: Journal of magnetism and magnetic materials 2020-03, Vol.497, p.166053, Article 166053
• Main Authors: Singh, Dushyant, Roy, Ranjan, Senthil Kumar, M.
• Format: Article
• Language: English
• Subjects: Anomalous Hall Effect; Correlation analysis; Crystallites; GIXRD; Hall effect; HRTEM; Magnetic multilayers; Magnetic properties; Magnetization; Magnetoresistance; Magnetoresistivity; Magnetron sputtering; Multilayers; Parameter sensitivity; Percolation; Scattering; Silicon; Transport properties
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2019.166053

•Si/Ni multilayers showed nanocrystalline grains from GIXRD and HRTEM studies.•Variation of magnetization at 20 kOe correlates with the grain size of Ni.•Anisotropic magnetoresistance is observed in the samples.•Skew scattering mechanism is responsible for AHE in the multilayers.•Maximum enhancements of about 33 times in RHSA and 24 times in Rs are observed. Influence of Si layer spacer on the magnetic and magnetotransport properties of the Si/Ni multilayers has been studied. The study is performed by investigating a series of [Si(tSi)/Ni(30Å)]20 multilayers prepared by DC magnetron sputtering process. The structural and microstructural studies suggest that the effective crystallites size increases with the decrease in tSi. The cross sectional TEM data reveal that the Si/Ni multilayers with tSi ≤ 10 Å are of discontinuous form. The magnetization (M20kOe) obtained at 20 kOe increases as tSi decreases and reaches towards the bulk value of Ni. This increase in M20kOe is due to the increase in effective size of the Ni nanocrystallites. The magnetotransport parameters such as saturated anomalous Hall resistance, anomalous Hall coefficient, Hall sensitivity and magnetoresistance ratio are found to gradually increase within 100 Å ≤ tSi ≤ 30 Å and then sharply increase till tSi = 10 Å due to surface and interface scattering. These parameters decrease when tSi further reduces down to 5 Å which is beyond the percolation threshold. The maximum enhancements of about 33 times in anomalous Hall resistance and 24 times in anomalous Hall coefficient are found at tSi = 10 Å when compared with the multilayers having tSi = 100 Å. The skew scattering is the dominant mechanism which is responsible for the anomalous Hall effect phenomena in the Si/Ni multilayers. The Si/Ni multilayers also show anisotropic magnetoresistance.