Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-22T20:34:26.775Z Has data issue: false hasContentIssue false
  • English
  • Français

Absolute Magnetometry Using Electron Holography: Magnetic Superlattices and Small Particles

Published online by Cambridge University Press:  29 November 2013

Marian Mankos ,
J.M. Cowley  and
M.R. Scheinfein
Get access

Extract

Synthesized magnetic structures are of interest due to their unique and unusual properties, which are governed by their micromagnetic structure. For example, giant-magnetoresistance (GMR) multilayer structures composed of magnetic layers separated by nonmagnetic spacers, and granular GMR films composed of magnetic and nonmagnetic metals exhibit phenomena whose interpretation requires knowledge of both the physical and micromagnetic structure at nanometer-length scales. Techniques for magnetic-microstructure imaging are based on the interaction between a probe and either the magnetic microstructure itself (magnetization) or a physical quantity related to the magnetization distribution (e.g., magnetostriction, magnetic induction). Transmission methods are sensitive to bulk magnetic microstructure averaged along the direction of the incident probe; surface structure is lost. Reflection techniques interact with the near-surface region and no information is obtained about the bulk structure aside from those properties that can be inferred from appropriate boundary conditions.

Electron-optical methods represent the widest class of high-spatial-resolution, magnetic-domain imaging techniques. The most advanced techniques provide the highest contrast, sensitivity, and point resolution (1 nm). Electron holography offers quantitative micromagnetic information at high spatial resolution, a feature missing in most magnetic-imaging techniques. Quantitative information can be extracted from the absolutely calibrated electron wavelength and a knowledge of electron phase shifts in electromagnetic fields. High sensitivity, nanometer spatial resolution, and absolute calibration make electron holography a powerful tool for examining magnetic microstructure. In electron holography, both the amplitude and phase of the transmitted electron waves can be recovered in contrast to conventional electron microscopy where only the intensity is available. The phase, containing information about the local distribution of electromagnetic fields, can be retrieved from an electron hologram.

Type
Magnetism on a Microscopic Scale
Information
MRS Bulletin , Volume 20 , Issue 10 , October 1995 , pp. 45 - 48
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Baibich, M.N., Broto, J.M., Fert, A., Van Dau, F. Nguyen, Petroff, F., Etienne, P., Creuzet, G., Friederich, A., and Chazelas, J., Phys. Rev. Lett. 61 (1988) p. 2472.CrossRefGoogle Scholar
2.Mosca, D.H., Petroff, F., Fert, A., Schroeder, P.A., Pratt, W.P. Jr., and Laloee, R., J. Magn. Mat. 94 (1991) p. L1.CrossRefGoogle Scholar
3.Scheinfein, M.R., Unguris, J., Pierce, D.T., Celotta, R.J., J. Appl. Phys. 67 (1990) p. 5932.CrossRefGoogle Scholar
4.Schaefer, R., Argyle, B.E., and Trouilloud, P.L., IEEE Trans. Magn. 28 (1992) p. 2644.CrossRefGoogle Scholar
5.Zhang, X., Joy, D.C., Zhang, Y., Hashimoto, T., Allard, L., and Nolan, T.A., Ultramicroscopy 51 (1993) p. 21.CrossRefGoogle Scholar
6.Gajdardziska-Josifovska, M., McCartney, M.R., de Ruijter, W.J., Smith, D.J., Weiss, J.K., and Zuo, J.M., Ultramicroscopy 50 (1993) p. 285.CrossRefGoogle Scholar
7.Mankos, M., Cowley, J.M., Chamberlin, R.V., Scheinfein, M.R., and Ayers, J.D., Proc. 51st Annual Meeting (Microscopy Society of America, 1993) p. 1026.Google Scholar
8.Altman, M., in Magnetic Materials: Microstructure and Properties, edited by Suzuki, T., Sugita, Y., Clemens, B.M., Ouchi, K., and Laughlin, D.E. (Mat. Res. Soc. Symp. Proc. 232 Pittsburgh, 1991) p. 125.Google Scholar
9.Scheinfein, M.R., Unguris, J., Blue, J.L., Coakley, K.J., Pierce, D.T., Celotta, R.J., and Ryan, P.J., Phys. Rev. B 43 (1991) p. 3395.CrossRefGoogle Scholar
10.Reimer, L., Transmission Electron Microscopy (Springer-Verlag, Berlin, 1984).CrossRefGoogle Scholar
11.Tonomura, A., Electron Holography (Springer-Verlag, Berlin, 1993).CrossRefGoogle Scholar
12.Tonomura, A., J. Magn. Mat. 35 (1983) p. 963.CrossRefGoogle Scholar
13.Mankos, M., Scheinfein, M.R., and Cowley, J.M., J. Appl. Phys. 75 (1994) p. 7418.CrossRefGoogle Scholar
14.Mankos, M., Yang, Z.J., Scheinfein, M.R., and Cowley, J.M., IEEE Trans. Magn. 30 (1994) p. 4497.CrossRefGoogle Scholar
15.Mankos, M., deHaan, P., Kambersky, V., Matteucci, G., McCartney, M.R., Yang, Z.J., Scheinfein, M.R., and Cowley, J.M., Electron Holography, Delta Series, edited by Tonomura, A., Allard, L., Pozzi, G., Joy, D., and Ono, Y. (Elsevier Science BV) (in press).Google Scholar
16.Mankos, M., Scheinfein, M.R., and Cowley, J.M., IEEE Trans. Magn. (in press).Google Scholar
17.Möllenstedt, G. and Düker, H., Z. Phys. 145 (1956) p. 377.CrossRefGoogle Scholar
18.Yang, Z.J. and Scheinfein, M.R., Appl. Phys. Lett. 66 (1995) p. 377.Google Scholar