Marek Malac

National Research Council Canada | NRC · National Institute for Nanotechnology (NINT)

The authors demonstrate that electron tomography allows accurate measurement of roughness of buried interfaces in multilayer samples. The method does not require the interface to be exposed at the surface of the sample, or does it require a laterally extended sample. Therefore, it enables quantitative site specific analysis of individual elements w...

We report on experimental and theoretical results on EELS from 12nm single-crystal gold films. Our results show that momentum resolution of the electrons gives insight into signatures of non-locality and quantum nature of the excitations.

of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

We explore the properties of elastic and inelastic scattering in a thick organic specimen, together with the mechanisms that provide contrast in a transmission electron microscope (TEM) and scanning-transmission electron microscope (STEM). Experimental data recorded from amorphous carbon are used to predict the bright-field image intensity, mass-th...

CAD drawings for V-groove and A-type column frame.

Electronic version of Fig 13 and 14 for NanoMi: An Open Source Electron Microscope Hardware and Software Platform. 10.1016/j.micron.2022.103362,

We outline a public license (open source) electron microscopy platform, referred to as NanoMi. NanoMi offers a modular, flexible electron microscope platform that can be utilized for a variety of applications, such as microscopy education and development of proof-of-principle experiments, and can be used to complement an existing experimental appar...

Bright-field transmission electron microscope (BFTEM) images exhibit spurious image intensity in the vacuum near the sample edge. The spurious intensity gradually decreases with increasing distance from the sample edge. By taking into account angular and energy loss distribution of the scattered electrons and lens aberrations, we can explain the or...

The higher order structure of the metaphase chromosome has been an enigma for over a century and several different models have been presented based on results obtained by a variety of techniques. Some disagreements in the results between methods have possibly arisen from artifacts caused during sample preparation such as staining and dehydration. T...

Germanium is typically used for solid-state electronics, fiber-optics, and infrared applications, due to its semiconducting behavior at optical and infrared wavelengths. In contrast, here we show that the germanium displays metallic nature and supports propagating surface plasmons in the deep ultraviolet (DUV) wavelengths, that is typically not pos...

Energy-filtering transmission electron microscopy (TEM) and bright-field TEM can be used to extract local sample thickness $t$ and to generate two-dimensional sample thickness maps. Electron tomography can be used to accurately verify the local $t$ . The relations of log-ratio of zero-loss filtered energy-filtering TEM beam intensity ( $I_{{\rm ZLP...

We investigated magnetic textures in a Sc-doped hexaferrite film by means of phase microscopy (PM) with a hole-free phase plate in a transmission electron microscope. In a zero magnetic field, the stripe-shaped magnetic domains coexist with magnetic bubbles. The magnetization in both magnetic domains was oriented perpendicular to the film and the d...

Our understanding of the inner structure of metaphase chromosomes remains inconclusive despite intensive studies using multiple imaging techniques. Transmission electron microscopy has been extensively used to visualize chromosome ultrastructure. This review summarizes recent results obtained using two transmission electron microscopy-based techniq...

It is well known that two DNA molecules are wrapped around histone octamers and folded together to form a single chromosome. However, the nucleosome fiber folding within a chromosome remains an enigma and the higher-order structure of chromosomes also is not understood. In this study, we employed electron diffraction (ED) which provides a non-invas...

Electron tomography (ET) has been used for quantitative measurement of shape and size of objects in three dimensions (3D) for many years. However, systematic investigation of repeatability and reproducibility of ET has not been evaluated in detail. To assess the reproducibility and repeatability of a protocol for measuring size and three-dimensiona...

In this paper, we review the current state of phase plate imaging in a transmission electron microscope (TEM). We focus especially on the hole-free phase plate (HFPP) design, also referred to as the Volta phase plate (VPP). We discuss the implementation, operating principles and applications of phase plate imaging. We provide an imaging theory that...

We are developing a modular (scanning) transmission electron microscope (S)TEM, referred to as NanoMi.

Higher-order Structure of Human Chromosomes Observed by Electron Tomography and Electron Diffraction - Misa Hayashida, Rinyaporn Phengchat, Darren Homeniuk, Marek Malac, Ken Harada, Tetsuya Akashi, Nobuko Ohmido, Kiichi Fukui

NanoMi: An Open Source (Scanning) Transmission Electron Microscope. - Marek Malac, Martin Cloutier, Mark Salomons, Sean Chen, Suliat Yakubu, Marcus Leeson, Jason Pitters, Doug Vick, Drew Price, Darren Homeniuk, Misa Hayashida, Ray Egerton

Substrate expansion/shrinkage makes it difficult to measure accurately the thermal expansion coefficient (TEC) of thin films. Furthermore, even very thin contamination layers can affect TEC measurements. We excluded the effects of contamination, quantified the effect of substrate, and succeeded in measuring the TEC of suspended single-layer graphen...

We present progress toward the quantitative interpretation of phase contrast images obtained using a hole-free phase plate (HFPP) in a transmission electron microscope (TEM). We consider a sinusoidal phase grating test object composed of ~5 nm deep groves in a ~13 nm thick amorphous silicon membrane. The periodic grating splits the beam current int...

While electron tomography can be used to visualize objects at nanoscale, it is difficult to perform reproducible quantitative measurements. Here we measure the shape and size of nanoparticles (NPs) in three dimensions (3D) using electron tomography. We evaluated the accuracy of maximum Feret diameter (Feretmax), minimum Feret diameter (Feretmini) a...

In-Situ Mass Thickness Calibrations Using MWCNTs - Volume 25 Supplement - M. Malac, D. Homeniuk, M. Hayashida, T. Fujii, T. Yaguchi, R.F. Egerton

Electron-beam shaping opens up novel imaging possibilities in electron microscopy (EM). The implementation of a phase or amplitude mask in the condenser lens system allows the generation of electron beams with various shapes. Non-diffractive Bessel beams (BBs) are of interest for numerous applications due to their extraordinary large depth of focus...

Fast electrons interacting with matter have been instrumental for probing bulk and surface photonic excitations including Cherenkov radiation and plasmons. Additionally, fast electrons are ideal to investigate unique bulk and longitudinal photonic modes in hyperbolic materials at large wavevectors difficult to probe optically. Here, we use momentum...

We report, for the first time, the three dimensional reconstruction (3D) of a transistor from a microprocessor chip and roughness of molecular electronic junction obtained by electron tomography with Hole Free Phase Plate (HFPP) imaging. The HFPP appears to enhance contrast between inorganic materials and also increase the visibility of interfaces...

Silicon is widely used as the material of choice for semiconductor and insulator applications in nanoelectronics, micro-electro-mechanical systems, solar cells, and on-chip photonics. In stark contrast, in this paper, we explore silicon’s metallic properties and show that it can support propagating surface plasmons, collective charge oscillations,...

We studied the charging behavior of an amorphous carbon thin film kept at liquid-nitrogen temperature under focused electron-beam irradiation. Negative charging of the thin film is observed. The charging is attributed to a local change in the work function of the thin film induced by electron-stimulated desorption similar to the working principle o...

Toward Quantitative Bright Field TEM Imaging of Ultra Thin Samples - Volume 24 Supplement - Takashi Fujii, Marek Malac, Emi Kano, Misa Hayashida, Toshie Yaguchi, Ray Egerton

Automation of Image Processing for Nano-beam Diffraction Measurements - Volume 24 Supplement - Darren Homeniuk, Francisco Paraguay Delgado, Marek Malac, Misa Hayashida

Hole Free Phase Plate Electron Tomography in Material Sciences - Volume 24 Supplement - Misa Hayashida, Amin Morteza Najarian, Richard McCreery, Marek Malac

Hole-Free Phase Plate Imaging of a Phase Grating - Volume 24 Supplement - Marek Malac, Misa Hayashida, Ken Harada, Keiko Shimada, Kodai Niitsu, Teddy Rowan, Marco Beleggia

Continuous Wavelet Transforms for Measuring Roughness of Nanoscale Interfaces - Volume 24 Supplement - Darren Homeniuk, Marek Malac, Misa Hayashida

Interface roughness is a critical parameter determining the performance of semiconductor devices. We show that a continuous wavelet transform is useful to describe not only the magnitude of the interface roughness, but also the spatial frequencies that describe the interface. We propose a simple presentation of the results that makes it convenient...

We report application of hole-free phase plate (HFPP) to imaging of magnetic skyrmion lattices. Using HFPP imaging, we observed skyrmions in FeGe, and succeeded in obtaining phase contrast images that reflect the sample magnetization distribution. According to the Aharonov-Bohm effect, the electron phase is shifted by the magnetic flux due to sampl...

We measured the linear thermal expansion coefficients of amorphous 5-30 nm thick SiN and 17 nm thick Formvar/Carbon (F/C) films using electron diffraction in a transmission electron microscope. Positive thermal expansion coefficient (TEC) was observed in SiN but negative coefficients in the F/C films. In case of amorphous carbon (aC) films, we coul...

A systematic study on charging of carbon thin films under intense electron-beam irradiation was performed in a transmission electron microscope to identify the underlying physics for the functionality of hole-free phase plates. Thin amorphous carbon films fabricated by different deposition techniques and single-layer graphene were studied. Clean th...

We developed a sample preparation method for 3D electron tomography using a focus-ion-beam-fabricated carbon square-shaped rod to observe the deformation of polystyrene nanoparticles on carbon. The method enables the observation of the interface between the particles and carbon substrate. Polystyrene nanoparticles are increasingly more deformed as...

Contamination and Charging of Amorphous Thin Films Suitable as Phase Plates for Phase-Contrast Transmission Electron Microscopy - Volume 23 Issue S1 - Simon Hettler, Peter Hermann, Manuel Dries, Martin Obermair, Dagmar Gerthsen, Marek Malac

Hole-Free Phase Plate Energy Filtering Imaging of Graphene: Toward Quantitative Hole-Free Phase Plate Imaging in a TEM - Volume 23 Issue S1 - Marek Malac, Emi Kano, Misa Hayashida, Masahiro Kawasaki, Sohei Motoki, Ray Egerton, Isamu Ishikawa, Yoshio Okura, Marco Beleggia

Temperature Measurement in a TEM using Electron Diffraction of Amorphous Films - Volume 23 Issue S1 - Misa Hayashida, Kai Cui, Marek Malac

The electronic structure of stoichiometric tin dioxide (SnO 2) is studied by probing its unoccupied states using the fine structure in the electron energy-loss spectra (EELS) at the oxygen-K (O-K) edge. The spectral measurements were performed both at room and at high temperatures (773 K) and compared to ab initio calculations carried out using the...

This work shows the comparison of high-resolution electron energy loss spectra (HR-EELS) in the low loss region (0−15 eV) to investigate the electronic structure from koechilinite Bi2MoO6 to rusellite Bi2WO6 varying the stoichiometric relation Bi2MoxW1−xO6. The effect of the Mo to W ratio on the bandgap energy was evaluated on individual particles....

Detailed simulations are necessary to correctly interpret the charge polarity of electron beam irradiated thin film patch. Relying on systematic simulations we provide guidelines and movies to interpret experimentally the polarity of the charged area, to be understood as the sign of the electrostatic potential developed under the beam with referenc...

Strong nanoscale light–matter interaction is often accompanied by ultraconfined photonic modes and large momentum polaritons existing far beyond the light cone. A direct probe of such phenomena is difficult due to the momentum mismatch of these modes with free space light, however, fast electron probes can reveal the fundamental quantum and spatial...

Many new materials emerging are strictly two dimensional (2D), often only one or two monolayers thick. They include transition metal dichalcogenides, such as MoS2 , and graphene. Graphene in particular appears to have many potential applications. Typically the crystalline film without contamination is of interest. Therefore, a reliable method is ne...

We analyze electron-beam induced carbon contamination in a transmission electron microscope. The study is performed on thin films potentially suitable as phase plates for phase-contrast transmission electron microscopy. Electron energy-loss spectroscopy and phase-plate imaging is utilized to analyze the contamination. The deposited contamination la...

Strong nanoscale light-matter interaction is often accompanied by ultra-confined photonic modes and large momentum polaritons existing far beyond the light cone. A direct probe of such phenomena is difficult due to the momentum mismatch of these modes with free space light however, fast electron probes can reveal the fundamental quantum and spatial...

We present a review of the recent progress in electron tomography applicable to materials science samples. We focus on practical high accuracy tomographic measurements and their applications. We follow the steps leading to a reconstructed 3D volume and discuss the effect of the individual steps on the suitability of the resulting 3D volume for quan...

A thin film irradiated by high-energy primary electrons (PE) emits secondary electrons (SE). The SE are either emitted from the sample (SEα) or travel within the sample (SEβ) [1]. Figure 1 illustrates the various types of SEs. The PEs, SEα and the SEβ affect, by modifying the film properties, the rate at which the irradiated sample area reaches a s...