Wave reversal mode: A new magnetization reversal mechanism in magnetic nanotubes

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:497

Article

Raviolo, Sofia^1,2  Arciniegas Jaimes, Diana M.¹  Bajales, Noelia^1,2  Escrig, Juan^3,4 

[1] Consejo Nacl Invest Cient & Tecn, IFEG, RA-5000 Cordoba, Argentina

[2] Univ Nacl Cordoba, FAMAF, RA-5000 Cordoba, Argentina

[3] Univ Santiago Chile, Dept Fis, USACH, Santiago 9170124, Chile

[4] Ctr Dev Nanosci & Nanotechnol CEDENNA, Santiago 9170124, Chile

关键词: Magnetic nanotubes;    Magnetization reversal mode;    Micromagnetic simulations;   

DOI  :  10.1016/j.jmmm.2019.165944

来源: Elsevier

【 摘 要 】

We have investigated the magnetic properties of 14 nm thick and 1 mu m long nickel and permalloy nanotubes with external diameters of 40 and 100 nm as a function of the angle theta at which the external magnetic field is applied. Our results show that the coercivity of 40 nm diameter nickel nanotubes follows a non-monotonic behavior from theta = 0 degrees up to theta = 60 degrees, while that corresponding to permalloy displays an increasing monotonic trend at the same angular range. At theta = 90 degrees, both materials evidence a sharp drop of the coercivity to zero, indicating that the reversal mechanism has changed to a pseudo-coherent rotation. On the other hand, nickel and permalloy nanotubes with 100 nm in diameter exhibit a similar angular dependence of the coercivity, reversing their magnetization through the nucleation and propagation of vortex domain walls for angles lower than 75 degrees. For theta = 90 degrees, a novel striking mechanism, the wave reversal mode (W), arises. This phenomenon leads to an unusual S-type shape in the hysteresis curves at those given parameters, which is until now an effect that has not been reported for these nanostructures.

【 授权许可】

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