Effective Co-rich ternary CoFeNi alloys for spintronics application

• Published in: Journal of alloys and compounds Vol. 854; p. 157171
• Main Authors: Milyaev, M.A., Bannikova, N.S., Naumova, L.I., Proglyado, V.V., Patrakov, E.I., Glazunov, N.P., Ustinov, V.V.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.02.2021; Elsevier BV
• Subjects: Alloys; Coercivity; CoFeNi; Composition; Crystal structure; Giant magnetoresistance; Iron; Magnetic properties; Magnetoresistivity; Multilayer; Multilayers; Nickel; Room temperature; Spintronics; Ternary alloys; Texture; Ternary alloys; Giant magnetoresistance; Multilayer; CoFeNi; Texture; Coercivity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157171

The dependence of crystal structure, hysteresis properties and magnetoresistance on composition of ternary CoFeNi alloy has been studied for glass/Ta/(Ni80Fe20)60Cr40/[CoFeNi/Cu(2.2 nm)]n/Ta multilayers. Two series of Co-rich CoFeNi alloys were used. In series (I) the Co content decreases from 90 to 67 at. %, Fe content increases from 10 to 20 at.% and Ni content – from 0 to 13 at.%. Series (II) includes alloys with a fixed Co content: Co70Fe30-xNix (x = 5, 10, 15 and 20). For each type of ternary alloys the multilayer composition was optimized in order to obtain maximum giant magnetoresistance (GMR). The highest GMR ratios of 30–33% at room temperature are revealed in multilayers of series (I) alloys. It has been established that the most effective CoFeNi alloys, using which the GMR multilayers have a high GMR ratio in combination with low coercivity, are located in a narrow region of the ternary diagram near the Co70Fe20Ni10 composition. A deviation of the ternary alloy composition from this optimal one leads either to a decrease in the GMR ratio, or to a significant increase of coercivity. •Magnetoresistance of CoFeNi/Cu multilayers with Co-rich ternary alloys reaches 33%.•Strong dependence of coercivity on composition of CoFeNi alloy is observed.•Usage of Co70Fe20Ni10 and Co67Fe20Ni13 alloys gives minimal coercivity.•Optimal alloys compositions locate in small part of ternary diagram near Co70Fe20Ni10.