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

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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Direct Observation of Domain Structure and Magnetization Reversal of Magnetic Thin Films Using Lorentz Transmission Electron Microscopy

Japanese Journal of Applied Physics ◽

10.1143/jjap.40.4891 ◽

2001 ◽

Vol 40 (Part 1, No. 8) ◽

pp. 4891-4896 ◽

Cited By ~ 4

Author(s):

Andrew Chak Chung Yu ◽

Amanda Petford-Long ◽

Terunobu Miyazaki

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Domain Structure ◽

Direct Observation ◽

Magnetization Reversal ◽

Magnetic Thin Films ◽

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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Transmission Electron Microscopy of Evaporated Perylene Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135289 ◽

1990 ◽

Vol 48 (2) ◽

pp. 336-337

Author(s):

C. Ewins ◽

J.R. Fryer

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Molecular Electronics ◽

High Vacuum ◽

Amorphous Layer ◽

Electric Heater ◽

Transmission Electron ◽

Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

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Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173479 ◽

1990 ◽

Vol 48 (4) ◽

pp. 68-69

Author(s):

J. T. Sizemore ◽

D. G. Schlom ◽

Z. J. Chen ◽

J. N. Eckstein ◽

I. Bozovic ◽

...

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Critical Currents ◽

Unit Cell ◽

X Ray Diffraction ◽

Cell Axis ◽

Transmission Electron ◽

Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

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