Effect of MgO Insertion between Topological Insulator Bi2Se3 and Ferromagnet NiFe Multilayer Structures

• We study ferromagnetic resonance (FMR) properties of topological insulator Bi2Se3 and ferromagnet NiFe (permalloy) multilayer structures. We found that Bi2Se3/NiFe shows two times larger magnetic damping than that of single NiFe, which indicates strong spin pumping exists in the interface between Bi2Se3 and NiFe. Also, 1 nm thick MgO layer was inserted into between Bi2Se3 and NiFe, where spin-pumping is expected to be suppressed. Bi2Se3/MgO/NiFe shows same amount of spin-pumping effect as observed in Bi2Se3/NiFe, while thin MgO layer can be beneficial for suppressing the formation of magnetic dead layer. These results show that 1 nm thick MgO can be utilized as a good spacer layer without a loss of spin-pumping in the multilayer structures with topological insulator.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

topological insulator

ferromagnetic resonance

spin pumping

magnetic

damping

magnetic dead layer

spin

driven

Physics

Publication and Content Type

ref (subject category)

art (subject category)