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Interface and temperature dependent magnetic properties in permalloy thin films and tunnel junction structures
J F Sierra1, V V Pryadun, S E Russek
1Departamento Física de la Materia Condensada C-III and Instituto "Nicolás Cabrera" Ciencia de Materiales, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Journal of Nanoscience and Nanotechnology
|November 22, 2011
Summary
Researchers studied Permalloy (Py) films and magnetic tunnel junctions, finding evidence of a spin reorientation transition around 60 K. Interface properties and atomic structure influence this low-temperature magnetic behavior.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Permalloy (Py) films are crucial in spintronic devices.
- Understanding their magnetic properties at low temperatures is essential for device performance.
Purpose of the Study:
- Investigate magnetization dynamics and field-dependent behavior of Py-based devices.
- Explore the influence of interfaces and structure on magnetic transitions.
Main Methods:
- Ferromagnetic resonance (FMR) using broadband vector network analyzer.
- Structural characterization via X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM).
- Micromagnetic simulations.
Main Results:
- Observed a thermally induced spin reorientation transition around 60 K in Py layers.
- Identified interface details, Py atomic structure (amorphous vs. textured), and dipolar coupling as influential factors.
- Micromagnetic simulations suggested enhanced surface anisotropy in Py films.
Conclusions:
- The low-temperature spin reorientation transition in Py films is sensitive to interface engineering and structural properties.
- Surface disorder may play a significant role in this transition.
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