Scanning Probe Methods for Magnetic Imaging
Previous chapters give an introduction to novel magnetic imaging methods based on the scanning tunneling microscope (STM) or on the scanning force microscope (SFM). While the STM is sensitive to the surface density of electronic states and to its spin dependence, the magnetic force microscope (MFM), as a special variant of the SFM, detects the magnetic stray field produced by a sample, or the response of the sample to the local stray field produced by the probe. The basic setup in tunneling or force microscopy establishes a unified experimental approach as the basis of all scanning probe methods (SPM). The present chapter summarizes the basic aspects underlying this approach, analyzes achievements as well as limitations, and introduces three additional SPM.
Microscopic imaging requires suitable interactions between a probe and a sample that allow one to map a physical quantity — in the present context, a magnetic property — at a certain lateral resolution. In the case of tomographic methods, a certain depth resolution is also required. Most frequently employed probe-sample interactions in magnetic imaging involve electron exchange and the analysis of the spin polarization, the reflection and transmission of light in terms of the Kerr and Faraday effects, and magneto-static field effects, as, e.g., being used in the Bitter colloid method. All these interactions, used as the basis of classical methods of magnetic imaging, can also be implemented in scanning probe strategies. The electron spin is detected by the spin-polarized STM(SPSTM). Kerr and Faraday effects are utilized in the magneto-optic scanning near-field optical microscope (MOSNOM). Near-surface stray fields produced by ferromagnetic or superconducting samples can be analyzed using scan ning SQUID (superconducting quantum interference device) microscopes (SSM) or microscopes based on other field sensors like Hall probes or magneto-resistive probes. Together with a discussion of some general aspects concerning probe-sample magnetic interactions, the MOSNOM and the SSM will be introduced in the following.
The high-resolution detection of spin resonances for imaging purposes has been the subject of considerable effort for quite some time. Also in this area classical approaches can be adapted to scanning probe strategies in order to analyze nuclear magnetic resonance (NMR), electron spin resonance (ESR), or ferromagnetic resonance (FMR) at a sub-micron scale. Some general information on the respective approaches of magnetic resonance force microscopy (MRFM) is provided as well by the following discussion.
KeywordsElectron Spin Resonance Magnetic Force Microscope Magnetic Imaging Scanning Force Microscope Mechanical Resonant Frequency
Unable to display preview. Download preview PDF.
- 1.U. Hartmann (ed.): Magnetic Multilayers and Giant Magnetoresistance, Springer Ser. in Surf. Sci. Vol. 37 (Springer, Berlin Heidelberg 1999)Google Scholar
- 2.S. Amelincks, D. van Dyck, J. van Landuyt, and G. van Tendeloo (eds.): Handbook of Microscopy (VCH, Weinheim 1997)Google Scholar
- 3.A. Hubert and R. Schäfer: Magnetic Domains — The Analysis of Magnetic Micrsostructures (Springer, Berlin Heidelberg 1998)Google Scholar
- 5.R. Wiesendanger and H.-J. Güntherodt (eds.): Scanning Tunneling Microscopy I–III, Springer Ser. in Surf. Sci. Vols. 20, 28, 29 (Springer, Berlin Heidelberg 1992–95)Google Scholar
- 6.J. Chen: Introduction to Scanning Tunneling Microscopy (Oxford Univ. Press, New York 1993)Google Scholar
- 7.R. Wiesendanger (ed.): Scanning Probe Microscopy, Springer Ser. in NanoSci. Techn. (Springer, Berlin Heidelberg 1998)Google Scholar
- 8.R. Wiesendanger: Scanning Probe Microscopy and Spectroscopy (Cambridge Univ. Press, Cambridge 1994)Google Scholar
- 9.T. Sakurai and Y. Watanabe (eds.): Advances in Scanning Probe Microscopy, Spinger Ser. in Adv. Mat. Res. (Springer, Berlin Heidelberg 2000)Google Scholar
- 12.S.D. Kevan (ed.): Angle-Resolved Photoemission (Elsevier, Amsterdam 1992)Google Scholar
- 13.L. Baumgarten, C.M. Schneider, H. Petersen, F. Schäfer, and J. Kirschner: Phys. Rev. Lett. 23, 492 (1980)Google Scholar
- 17.M.S. Altmann, H. Pinkvos, J. Hurst, H. Poppa, G. Marx, and E. Bauer: Mat. Res. Soc. Symp. Proc. 232, 125 (1991)Google Scholar
- 18.K. Koike and K. Hayakawa: Jpn. J. Appl. Phys. 23, L 187 (1984)Google Scholar
- 19.S.W. Lovesey: Theory of Neutron Scattering from Condensed Matter (Clarendon Press, Oxford 1984)Google Scholar
- 22.A. Carey and E.D. Isaac: Magnetic Domains and Techniques for Their Observation (Academic Press, New York 1966)Google Scholar
- 26.W.G. Jenks, I.M. Thomas, and J.P. Wikswo Jr. in: Encyclopedia of Applied Physics, G.L. Trigg, E.S. Vera, and W. Greulich (eds.) Vol. 19, p. 457 (VCH, New York 1997)Google Scholar
- 31.H. Weinstock (ed.): SQUID Sensors — Fundamentals, Fabrication and Applications (Uluwer, Dodrecht 1996)Google Scholar
- 32.F.P. Rogers, Master's Thesis (MIT, Cambridge 1983)Google Scholar
- 40.P. Pitzius, V. Dworak, and U. Hartmann in: Proc. ISEC'97 Conf., H. Koch, S. Knappe (eds.) Vol. 3, p. 359 (PTB, Braunschweig, 1997)Google Scholar
- 42.G. Alzetta, E. Arminando, C. Ascoli, and A. Zozzini: Il Nuovo Cimento B 52, 392 (1967)Google Scholar
- 46.C.S. Yannoni, O. Züger, D. Rugar, and J.S. Sidles in Encyclopedia of Magnetic Resonance, D.M. Grant and R.K. Harris (eds.), p. 2093 (Wiley, Chichester 1996)Google Scholar
- 54.Z. Zhang, P.C. Hammel, M. Midzor, M.L. Roukes, and J.R. Childress: Appl. Phys. Lett. 73,1959 (1998)Google Scholar
- 55.D. Rugar, O. Züger, S. Hoen, C.S. Yannoni, H.M. Vieth, and R.D. Kendrick: Science 264, 1560 (1994)Google Scholar
- 58.T.A. Barrett, C.R. Miers, H.A. Sommer, K. Mochizuki, and J.T. Markert: Appl. Phys. Lett. 83, 6235 (1998)Google Scholar
- 63.O. Züger and D. Rugar: J. Appl. Phys. 63, 611 (1994)Google Scholar