Kajian Pengaruh Dimensi Dan Geometri Terhadap Pergeseran Domain Wall Magnetik Pada Lapisan Tipis Permalloy (Ni Fe )
| Main Authors: | , ANISA INDRIAWATI, , Dr. Edi Suharyadi |
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| Format: | Thesis NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2014
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/133401/ http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=74059 |
Daftar Isi:
- Research of magnetic domain wall propagation of permalloy thin layer has been investigated. Magnetic domain wall propagation is analyzed by using Object Oriented Micromagnetic Framework (OOMMF) software based on Landau-Lifshitz Gilbert (LLG). The purpose of this research is to give the explanations on the effect of geometry and dimension toward propagations pattern of magnetic domain wall, magnetization�s values, shift velocity, and magnetic domain wall anisotropy energy. In this study, permalloy geometry are squares and ellipses. Thickness variation used is 1, 2, and 3 nm, with square size of 100 nm � 100 nm. Variation of square size used is at 100 nm � 100 nm, 100 nm � 120 nm, and 100 nm � 140 nm in thickness fixed at 3 nm. Simulations are done by applying external magnetic field in the +x direction. Applied external magnetic field is 0 Oe to 1000 Oe, which consist of 2500 steps. Simulation results show all of variation, no mater it�s thickness or size, have all the magnetitation at about 0,99. Size variations are 100 � 100 , 100 � 120 , dan 100 � 140 , then the thickness�s are 1 nm, 2 nm, and 3 nm. The velocity of the magnetic domain wall propagation is highest in the thin layer of permalloy as the length, width or axis of 100 nm � 100 nm with a thickness of 1 nm, that is equal to 18.755 m / s (square) that occured at a critical field of 36.4 Oe and 18,600 (ellipse) that occurs at a critical field of 38.8 Oe. Anisotropy energy is minimum when it approaches saturation, for all variations. Square geometry requires an external magnetic field greater than the minimum is reached for ellipse. Polarization of ellipse geometry is spread acroos the surface thus it requires small external field to reach saturation and to minimize anisotropy energy. The maximum velocity of permalloy thin layer with square geometri is higher than ellipse, because when condition is multidomain, it has more +x direction of magnetic moments. The effect of dimension on the propagation of magnetic domain wall xvii xvii related to the number of magnetic moments that have to be aligned. The more magnetic moments number, the higher external magnetic field required. Keywords: Propagation of magnetic domain wall, Tunneling Magneto Resistance (TMR), simulation mikromagnetik, LLG equation