Observation of magnetic domain structure in Terfenol-D by scanning electron acoustic microscopy

• Published in: Journal of magnetism and magnetic materials 2008-03, Vol.320 (6), p.978-982
• Main Authors: Song, H.Z., Li, Y.X., Zeng, J.T., Li, G.R., Yin, Q.R.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain effects, magnetization curves, and hysteresis; Domain walls and domain structure; Exact sciences and technology; Magnetic domain; Magnetic properties and materials; MFM; Physics; Scanning electron acoustic microscopy; Terfenol-D
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2007.10.001

The magnetic domain structure in oriented Tb 0.3Dy 0.7Fe 1.92 (Terfenol-D) is investigated by scanning electron acoustic microscopy (SEAM) in a wide frequency range from 75 to 530 kHz. Both secondary electron image and electron acoustic image can be obtained in situ simultaneously. By changing the modulation frequencies, the SEAM can be used as an effective nondestructive method to observe not only the surface topography and domain structure but also the subsurface domain structure and defects. The magnetic domain structure is verified by magnetic force microscopy (MFM). Furthermore, magnetic domains can be observed in both linear and nonlinear imaging modes by SEAM. The contributions to the image contrast are related to the signal generation through the piezomagnetic coupling mechanism, magnetostrictive coupling mechanism, and thermal-wave coupling mechanism.