Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-24T10:50:04.249Z Has data issue: false hasContentIssue false
  • English
  • Français

High Resolution Imaging of Magnetization

Published online by Cambridge University Press:  29 November 2013

D.T. Pierce ,
J. Unguris  and
R.J. Celotta
Get access

Extract

In 1907 Weiss postulated that a ferro-magnet has many small regions or domains that are spontaneously magnetized below the Curie temperature. In an unmagnetized ferromagnetic specimen the domains form so as to minimize the free energy, which includes contributions from the exchange energy, crystal and shape anisotropy energy, magnetostrictive energy, and so on. The actual size and shape of domains can only be calculated for the simplest geometries and for idealized materials. To investigate magnetic microstructure and how it determines macroscopic magnetic properties, we want to be able to see domain configurations and understand how the magnetic microstructure is changed by external influences and varying material properties. The observation of microscopic domain configurations can aid in engineering magnetic materials with desired magnetic properties.

Domains were first observed using the Bitter method in which fine magnetic particles collect on the surface of a specimen in the field gradients at domain walls. Domains can also be observed by electron microscopy, with scanning electron microscopy, or at higher resolution with transmission electron microscopy. Specimens must be thinned to about 100 nm for use in the TEM. This, in turn, changes their magnetic properties. The magneto-optic Kerr effect has the advantage that the signal is directly related to the magnetization of the specimen and not just to the leakage fields or internal magnetic fields as in the methods mentioned above. This technique has the disadvantage of being limited to an optical resolution of typically 1μm.

Type
Magnetism and Magnetic Materials
Information
MRS Bulletin , Volume 13 , Issue 6 , June 1988 , pp. 19 - 23
Copyright
Copyright © Materials Research Society 1988

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.Weiss, P., J. Phys. 6 (1907) p. 661.Google Scholar
2.Bitter, F., Phys. Rev. 38 (1931) p. 1903.CrossRefGoogle Scholar
3.Williams, H.S., Bozorth, R.M., and Shockley, W., Phys. Rev. 75 (1949) p. 155.CrossRefGoogle Scholar
4.Newbury, D.E., Joy, D.C., Echlin, P., Fiori, C.E., and Goldstein, J.I., Advanced Scanning Electron Microscopy and X-Ray Microanalysis (Plenum Press, New York, 1986) p. 147.CrossRefGoogle Scholar
5.Jakubovics, J.P., in Electron Microscopy in Materials Science Part IV, edited by Ruedl, E. and Valdre, U. (Commission of the European Communities, Brussels, 1973) p. 1305.Google Scholar
6.Kranz, J. and Hubert, A., Z. Angew. Phys. 15 (1963) p. 220.Google Scholar
7.Feder, R., Polarized Electrons in Surface Physics (World Scientific, Singapore, 1985).Google Scholar
8.Celotta, R.J. and Pierce, D.T., Science 234 (1986) p. 333.CrossRefGoogle Scholar
9.Unguris, J., Pierce, D.T., Galejs, A., and Celotta, R.J., Phys. Rev. Lett. 49 (1982) p. 72.CrossRefGoogle Scholar
10.Glazer, J. and Tosatti, E., Solid State Commun. 52 (1984) p. 905.CrossRefGoogle Scholar
11.Penn, D.R., Apell, S.P. and Girvin, S.M., Phys. Rev. Lett. 55 (1985) p. 518.CrossRefGoogle Scholar
12.Kisker, E., Gudat, W., and Schroeder, K., Solid State Commun. 44 (1982) p. 591.CrossRefGoogle Scholar
13.Hopster, H., Raue, R., Kisker, E., Guntherodt, G., and Campagna, M., Phys. Rev. Lett. 50 (1983) p. 70.CrossRefGoogle Scholar
14.Celotta, R.J. and Pierce, D.T., in Microbeam Analysis - 1982, edited by Heinrich, K.F.J. (San Francisco Press, 1982) p. 469.Google Scholar
15.Kessler, J., Polarized Electrons (Springer, Berlin, 1985) p. 230.CrossRefGoogle Scholar
16.Koike, K. and Hayakawa, K., Jpn. J. Appl. Phys. 23 (1984) p. L187.CrossRefGoogle Scholar
17.Koike, K., Matsuyama, H., and Hayakawa, K., Scanning Microscopy Supplement 1 (1987) p. 241.Google Scholar
18.Unguris, J., Hembree, G.G., Celotta, R.J., and Pierce, D.T., J. Microscopy 139 (1985) p. RP–1.CrossRefGoogle Scholar
19.Unguris, J., Pierce, D.T., and Celotta, R.J., Rev. Sci. Instrum. 57 (1986) p. 1314.CrossRefGoogle Scholar
20.Clough, S.P. and Eberle, W.J., PHI Interface 10 (1987) p. 4.Google Scholar
21.Hembree, G.G., Unguris, J., Celotta, R.J., and Pierce, D.T., Scanning Microscopy Supplement 1 (1987) p. 229.Google Scholar
22.Livingston, J.D., J. Appl. Phys. 57 (1985) p. 3555.CrossRefGoogle Scholar
23.Robbins, J.L., Celotta, R.J., Unguris, J., Pierce, D.T., Jonker, B.T., and Prinz, G.A., Appl. Phys. Lett. (in press).Google Scholar