# IBM Journal of Research and Development

## Volume 55 Issue 4 • July-Aug. 2011

Cathode Lens Microscopy for Nanoscience

This issue of the IBM journal describes recent advances in the field of nanoscience, with an emphasis on cathode lens-based microscopy methods, including LEEM (low-energy electron microscopy), PEEM (photoemission electron microscopy), and other related analytical approaches. Papers highlight scientific advances and instrumental developments on topics that include thin films, organic films, surface chemistry, magnetism, time-resolved methods, and various novel applications of microscopy in material science.

## Filter Results

Displaying Results 1 - 18 of 18
• ### Cover 1

Publication Year: 2011, Page(s): C1
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Publication Year: 2011, Page(s): 1
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• ### Preface: Cathode Lens Microscopy for Nanoscience

Publication Year: 2011, Page(s):0:1 - 0:3
| PDF (56 KB)
• ### Low-energy electron microscopy and spectroscopy with ESCHER: Status and prospects

Publication Year: 2011, Page(s):1:1 - 1:7
Cited by:  Patents (2)
| | PDF (4123 KB)

We describe the layout and the capabilities of a new aberration-corrected low-energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) facility, which features real- and reciprocal-space spectroscopy. This new setup, named Electronic, Structural, and Chemical Nanoimaging in Real Time (ESCHER), was recently installed at Leiden University. It has three major instrumentation-rel... View full abstract»

• ### Scanning transmission low-energy electron microscopy

Publication Year: 2011, Page(s):2:1 - 2:6
| | PDF (3725 KB)

We discuss an extension to the transmission mode of the cathode-lens-equipped scanning electron microscope, enabling operation down to the lowest energies of electrons. Penetration of electrons through free-standing ultrathin films is examined along the full energy scale, and the contribution of the secondary electrons (SEs), released near the bottom surface of the sample, is shown, enhancing the ... View full abstract»

• ### Laplacian and caustic imaging theories of MEM work-function contrast

Publication Year: 2011, Page(s):3:1 - 3:8
| | PDF (1355 KB)

We apply geometrical, Laplacian, and caustic imaging theories to simulate the mirror electron microscope (MEM) contrast arising from a surface phase boundary associated with a discontinuity in work function. The key approximations inherent in the theories are highlighted and investigated within strong and weak scattering regimes from the work-function test object. For strongly varying potentials, ... View full abstract»

• ### Laser-excited PEEM using a fully tunable fs-laser system

Publication Year: 2011, Page(s):4:1 - 4:8
| | PDF (1669 KB)

The ferroelectric domain structure on a (001) surface of a$BaTiO_{3}$single crystal prepared under ultrahigh vacuum conditions is imaged by laser-excited photoemission electron microscopy (PEEM). The PEEM images allow for discrimination of three domain types by their different photoemission yields. To characterize the contrast betwe... View full abstract»

• ### Partial secondary electron-yield NEXAFS spectromicroscopy with an energy-filtered X-PEEM

Publication Year: 2011, Page(s):5:1 - 5:6
| | PDF (2140 KB)

The narrow energy band pass of an energy-filtered x-ray photoemission electron microscope (X-PEEM) can lead to unusual artifacts when used for spatially resolved near-edge x-ray absorption fine structure (NEXAFS) spectroscopy and imaging of organic surfaces. Work-function differences and the rapid work-function change with radiation exposure can impair quantitative chemical analysis by NEXAFS and ... View full abstract»

• ### Nanoscale 3-D$(E, k_{x}, k_{y})$band structure imaging on graphene and intercalated graphene

Publication Year: 2011, Page(s):6:1 - 6:6
| | PDF (6219 KB)

An x-ray photoemission electron microscope (X-PEEM) equipped with a hemispherical energy analyzer is capable of fast acquisition of momentum-resolved photoelectron angular distribution patterns in a complete cone. We have applied this technique to observe the 3-D$(E, k_{x}, k_{y})$electronic band structure of zero-, one-, and two-mo... View full abstract»

• ### Highly uniform step and terrace structures on SiC(0001) surfaces

Publication Year: 2011, Page(s):7:1 - 7:6
| | PDF (3476 KB)

Highly uniform step and termination structures on 4H- and 6H-SiC(0001) surfaces have been prepared via moderate annealing in disilane. Atomic force microscopy and dark-field low-energy electron microscopy imaging indicate single-phase terminations separated solely by half-unit-cell-height steps, driven by stacking fault energy. The atomic structure of 4H-SiC(0001)-<formula formulatype="inline"&... View full abstract»

• ### In situ oxidation of ultrathin silver films on Ni(111)

Publication Year: 2011, Page(s):8:1 - 8:7
| | PDF (8922 KB)

Oxidation of silver films of one- and two-monolayer thicknesses on the Ni(111) surface was investigated by low-energy electron microscopy at temperatures of 500 and 600 K. Additionally, intensity–voltage curves were measured in situ during oxidation to reveal the local film structure on a nanometer scale. At both temperatures, we find that exposure to molecular oxygen leads to the destabilization ... View full abstract»

• ### Shape, orientation, and crystalline composition of silver islands on Si(111)

Publication Year: 2011, Page(s):9:1 - 9:6
| | PDF (3162 KB)

Photoemission electron microscopy and spot profile analyzing low-energy electron diffraction have been used to study the temperature-dependent growth of Ag islands on a Si(111) surface. Depending on growth temperature, various island shapes can be formed. At low temperatures, polygonic islands are formed, consisting of both Ag(001) and Ag(111) crystal orientations. At higher temperatures, islands ... View full abstract»

• ### Ga droplet surface dynamics during Langmuir evaporation of GaAs

Publication Year: 2011, Page(s):10:1 - 10:7
| | PDF (6585 KB)

We describe the design and application of a low-energy electron microscope (LEEM) dedicated to the study of III–V materials. Recent studies of Langmuir (free) evaporation of GaAs(001) have been reviewed. Running Ga droplets are observed, and the motion is predicted and shown to slow and stop near a characteristic temperature. Striking bursts of “daughter” droplet nucleation accompany the coalescen... View full abstract»

• ### In adsorption on Si(112) and its impact on Ge growth

Publication Year: 2011, Page(s):11:1 - 11:8
| | PDF (12799 KB)

The change of the Si(112) surface morphology and structure induced by In adsorption, as well as the impact of In preadsorption on the growth kinetics and island morphology in Ge/Si(112) epitaxy, has been investigated by means of low-energy electron microscopy and diffraction. The intrinsically faceted Si(112) surface is smoothed upon In saturation. In contrast to a previously reported (7 <formu... View full abstract»

• ### An XMCD-PEEM study on magnetized Dy-doped Nd-Fe-B permanent magnets

Publication Year: 2011, Page(s):12:1 - 12:6
| | PDF (6601 KB)

We have succeeded in developing a method for photoemission electron microscopy (PEEM) on fully magnetized ferromagnetic bulk samples and have applied this technique to Dy-doped Nd-Fe-B permanent magnets. Remanence magnetization of the sample was approximately 1.2 T, and its dimension was 3 <formula formulatype="inline"><tex Notation="TeX">$\times$</tex></formula> 3 <for... View full abstract»

• ### Direct metallographic analysis of an iron meteorite using hard x-ray photoelectron emission microscopy

Publication Year: 2011, Page(s):13:1 - 13:5
| | PDF (3363 KB)

The local structure of an iron meteorite was analyzed using photoemission electron microscopy (PEEM) and hard x-rays. The x-ray absorption fine-structure spectrum was obtained for each pixel in the PEEM image. The spectrum provides a wide variety of information, e.g., chemical composition, electronic structure, and lattice structure, in the interface region of the Widmanstätten structure. The shap... View full abstract»

• ### Thermionic electron emission microscopy of metal-oxide multilayers on tungsten

Publication Year: 2011, Page(s):14:1 - 14:6
Cited by:  Papers (4)
| | PDF (1188 KB)

Thick (200-nm) layers of reactively sputtered BaO and Sc$_{2}$O$_{3}$on tungsten foil are imaged with thermionic electron emission microscopy (ThEEM). The scandia films are observed to show what we have named the “window effect,” i.e., apparent electron transparency i... View full abstract»

• ### Diffusion and submonolayer growth of para-sexiphenyl on Ir(111) and Ir(111)-supported graphene

Publication Year: 2011, Page(s):15:1 - 15:7
| | PDF (3518 KB)

Transparent, flexible, and conductive graphene sheets form an ideal substrate for the fabrication of organic light-emitting diodes. In order to obtain an optimal final device, it is vitally important to understand the underlying nucleation and growth processes. Here, the growth of para-sexiphenyl (6P) thin films on Ir(111)-supported graphene and on Ir(111) has been investigated. Special attention ... View full abstract»

## Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

The following IBM journal articles are freely available for all users to view:

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## Meet Our Editors

Editor-in-Chief
Rachel D'Annucci Henriquez
IBM T. J. Watson Research Center