Epitaxial Nd-Fe-B films: Growth, texture, magnetism and the influence of mechanical elongation

The work in this thesis focuses on the preparation of epitaxial Nd-Fe-B thin films using pulsed laser deposition for good hard magnetic properties. They are suitable for a basic understanding of the intrinsic magnetic properties. Compositional control was necessary to achieve phase formation with improved magnetic properties. Nd-Fe-B samples were prepared on single crystal MgO (001) substrates with different buffer layers in order to obtain good textures with different surface morphology. The smooth and continuous epitaxial films were suitable for performing magnetization measurements under stress. Although the magnetostriction is easily neglected in the Nd2Fe14B compound, distinguishable inverse magnetostriction was observed by conventional tensile elongation with a flexible substrate. As a result, anisotropic strain in the film, which breaks the in-plane symmetry, affected the opening angle during the spin reorientation. Therefore an elliptical distortion of the in-plane anisotropy below the spin reorientation temperature of Nd2Fe14B was obtained, whereas the transition temperature itself was not influenced significantly.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Technische Universität Dresden

Year

2009

Author dc:creator

• Kwon, Ah-Ram

Contributors dc:contributor

• Schultz, Ludwig
• Meyer, Dirk
• Fidler, Josef

• Nd-Fe-B films
• Pulsed laser deposition
• hard magnetism
• spin reorientation
• strain
• Nd-Fe-B-Schichten
• gepulste Laserdeposition
• hartmagnetische Eigenschaften
• Spinreorientierung
• Dehnung