Related Experiment Video
Updated: Feb 12, 2026

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx
Published on: May 13, 2020
Phase retrieval using through-focus images in Lorentz transmission electron microscopy.
Takahiro Tamura1, Yukinori Nakane1, Hiroshi Nakajima2
1Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
We developed a new phase retrieval method using through-focus images in Lorentz transmission electron microscopy (LTEM) to observe magnetic domain structures. This conjugate gradient maximum likelihood (CG-MAL) approach offers improved convergence for magnetic bubble analysis.
Area of Science:
- Materials Science
- Physics
- Electron Microscopy
Background:
- Lorentz transmission electron microscopy (LTEM) is crucial for visualizing magnetic domain structures.
- Accurate phase retrieval is essential for reconstructing high-resolution images from LTEM data.
- Existing iterative phase retrieval methods can face challenges with convergence and accuracy.
Purpose of the Study:
- To introduce and evaluate a novel phase retrieval method, conjugate gradient maximum likelihood (CG-MAL), for LTEM.
- To assess the effectiveness of CG-MAL using simulated and experimental through-focus images of magnetic bubbles.
- To demonstrate the method's capability in reconstructing magnetic domain structures.
Main Methods:
- Phase retrieval using the maximum likelihood method combined with the conjugate gradient method (CG-MAL).
- Utilizing a series of through-focus images of magnetic bubbles with defocus values ranging from -3 mm to 3 mm.
- Validation through both simulated data and experimental LTEM images.
Main Results:
- Successful reconstruction of magnetic domain structures for magnetic bubbles from both simulated and experimental data.
- Demonstrated superior convergence behavior of the CG-MAL method compared to other iterative phase retrieval techniques.
- The method effectively processed images across a wide defocus range (-3 mm to 3 mm).
Conclusions:
- The CG-MAL method provides an effective and robust approach for phase retrieval in LTEM.
- This technique significantly improves the observation of magnetic domain structures, particularly for magnetic bubbles.
- CG-MAL shows broad applicability for analyzing diverse magnetic domain structures using highly defocused through-focus images.
Related Concept Videos
Transmission Electron Microscopy
Overview of Electron Microscopy
Scanning Electron Microscopy
Fundamental Principles
Accelerated...
Immunogold Electron Microscopy
Cryo-electron Microscopy
Retrieval
Recall involves accessing information without cues, such as during an essay test, where individuals must retrieve facts and concepts from memory unaided. Another example is remembering the name of a colleague...

