Nano-Structured Magnetic Films Investigated with Lorentz Transmission Electron Microscopy and Electron Holography

This paper aims at applying advanced transmission electron microscopy (TEM) to functional materials, such as ultra-soft magnetic films for high-frequency inductors, to reveal the structure-property relationship. The ultimate goal is to delineate a more quantitative way to obtain information of the magnetic induction and local magnetization. Nano-crystalline Fe-Zr-N films have been prepared by DC magnetron reactive sputtering with a thickness between 50 and 500 nm. Conventional TEM and selected area diffraction (SAD), reveal crystallites of sizes ranging between 2 and 30 nm. The films showed a granular or hillock type of roughness with an rms amplitude of 5 nm. In particular this paper concentrates on an analysis of phase maps in electron holography and intensity maps in Lorentz transmission electron microscopy including the thickness variation over the sample. For a particular statistical description of the roughness and values for the roughness it is shown that analytical expressions can be obtained. We demonstrate that starting from the concept of the vector potential in classical electrodynamics these results can be achieved assuming independent stationary Gaussian distributions for the height correlation functions.

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Nano-Structured Thin Films: A Lorentz Transmission Electron Microscopy and Electron Holography Study

Materials Science Forum - PRICM-5 ◽

10.4028/0-87849-960-1.4241 ◽

2005 ◽

pp. 4241-4250

Author(s):

Jeff Th.M. de Hosson ◽

Hans A. De Raedt

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Electron Holography ◽

Transmission Electron ◽

Lorentz Transmission Electron Microscopy

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Quantitative Magnetic Imaging of Skyrmions and Magnetic Thin Layers by Lorentz Transmission Electron Microscopy and Electron Holography

Microscopy and Microanalysis ◽

10.1017/s1431927618005135 ◽

2018 ◽

Vol 24 (S1) ◽

pp. 928-929

Author(s):

Toshiaki Tanigaki ◽

Tetsuya Akashi

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Thin Layers ◽

Electron Holography ◽

Magnetic Imaging ◽

Transmission Electron ◽

Lorentz Transmission Electron Microscopy

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Electron holography in materials science

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087665 ◽

1991 ◽

Vol 49 ◽

pp. 670-671

Author(s):

Hannes Lichte ◽

Edgar Voelkl

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Materials Science ◽

Fourier Spectrum ◽

Object Wave ◽

Electron Holography ◽

Reconstruction Procedure ◽

Numerical Reconstruction ◽

Transmission Electron ◽

Unique Interpretation

The object wave o(x,y) = a(x,y)exp(iφ(x,y)) at the exit face of the specimen is described by two real functions, i.e. amplitude a(x,y) and phase φ(x,y). In stead of o(x,y), however, in conventional transmission electron microscopy one records only the real intensity I(x,y) of the image wave b(x,y) loosing the image phase. In addition, referred to the object wave, b(x,y) is heavily distorted by the aberrations of the microscope giving rise to loss of resolution. Dealing with strong objects, a unique interpretation of the micrograph in terms of amplitude and phase of the object is not possible. According to Gabor, holography helps in that it records the image wave completely by both amplitude and phase. Subsequently, by means of a numerical reconstruction procedure, b(x,y) is deconvoluted from aberrations to retrieve o(x,y). Likewise, the Fourier spectrum of the object wave is at hand. Without the restrictions sketched above, the investigation of the object can be performed by different reconstruction procedures on one hologram. The holograms were taken by means of a Philips EM420-FEG with an electron biprism at 100 kV.

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Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087215 ◽

1991 ◽

Vol 49 ◽

pp. 580-581

Author(s):

L. Tang ◽

G. Thomas ◽

M. R. Khan ◽

S. L. Duan

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Magnetic Recording ◽

Magnetic Thin Films ◽

Magnetic Films ◽

Substrate Bias ◽

Epitaxial Relationship ◽

Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

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