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Papers by Bene Poelsema

Physical Review Materials, Jun 24, 2019

In situ STM Ergebnisse der elektrochemischen Deposition von Co auf Cu(001) in einer chloridhaltig... more In situ STM Ergebnisse der elektrochemischen Deposition von Co auf Cu(001) in einer chloridhaltigen wasrigen Losung (8 mM KCl, 1mM CoCl2) werden vorgestellt. Es hat sich erwiesen, das eine Erhohung des pH-Wertes entscheidend ist, um die Kobaltdeposition auf Cu(001) zu ermoglichen, ohne das diese von einer massiven Wasserstoffentwicklung beeintrachtigt wird. Eine Vorbedeckung von Chloridanionen wird benutzt, um die Oberflache von einer Oxidschicht zu befreien. Hierbei wird die Cu(001) Oberflache mit einer 10 mM HCl wasrigen Losung vorbehandelt. STM Ergebnisse deuten auf eine Oberflachenlegierungsbildung von Kobalt und Kupfer hin. Es erweist sich, das der Abscheidungs- und Auflosungsprozes nach einiger Zeit des Zykelns reversibel wird. Es werden Struktur und Morphologie von Kobaltfilmen verschiedener Dicke vorgestellt.

Bulletin of the American Physical Society, Mar 17, 2016

Springer Tracts in Modern Physics, 1989

Journal of Physical Chemistry C, Apr 7, 2017

Alloying, de-alloying and reentrant alloying in (sub-)monolayer growth of Ag on Pt(111) 2 Abstrac... more Alloying, de-alloying and reentrant alloying in (sub-)monolayer growth of Ag on Pt(111) 2 Abstract. An in-situ nanoscopic investigation of the prototypical surface alloying system Ag/Pt(111) is reported. The morphology and the structure of the ultrathin Ag-Pt film is studied using Low Energy Electron Microscopy during growth at about 800 K. An amazingly rich dynamic behaviour is uncovered in which stress relieve plays a governing role. Initial growth leads to surface alloying with prolonged and retarded nucleation of ad-islands. Beyond 50% coverage de-alloying proceeds, joined by partial segregation of Pt towards the centre of large islands in violent processes. Upon coalescence the irregularly shaped vacancy clusters are filled by segregating Pt, which then take a compact shape (black spots). As a result at around 85% coverage the strain of the initially pseudo-morphological film is almost completely relieved and Pt-segregation is at its maximum. Further deposition of Ag leads to transient reentrant alloying and recovery of the pseudo-morphological layer. The black spots persist even in/on several layers thick films. Ex-situ atomic force microscopy data confirm that these are constituted by probably amorphous Pt(-rich) structures. The (sub-)monolayer films are very much heterogeneous.

Nanoscience and Technology, 2016

While the default imaging mode in HIM uses secondary electrons, backscattered helium or neon cont... more While the default imaging mode in HIM uses secondary electrons, backscattered helium or neon contains valuable information about the sample composition and structure. In this chapter, we will discuss how backscattered helium can be used to obtain information about buried structures and provide qualitative elemental contrast. The discussion is extended to the use of channeling to increase image quality and obtain crystallographic information. As an example, we demonstrate that the period of a dislocation network in a film only two monolayers thick can be obtained with atomic precision.

Springer Tracts in Modern Physics

Verhandlungen der Deutschen Physikalischen Gesellschaft, 2008

Physical Review Materials, Jun 24, 2019

In situ STM Ergebnisse der elektrochemischen Deposition von Co auf Cu(001) in einer chloridhaltig... more In situ STM Ergebnisse der elektrochemischen Deposition von Co auf Cu(001) in einer chloridhaltigen wasrigen Losung (8 mM KCl, 1mM CoCl2) werden vorgestellt. Es hat sich erwiesen, das eine Erhohung des pH-Wertes entscheidend ist, um die Kobaltdeposition auf Cu(001) zu ermoglichen, ohne das diese von einer massiven Wasserstoffentwicklung beeintrachtigt wird. Eine Vorbedeckung von Chloridanionen wird benutzt, um die Oberflache von einer Oxidschicht zu befreien. Hierbei wird die Cu(001) Oberflache mit einer 10 mM HCl wasrigen Losung vorbehandelt. STM Ergebnisse deuten auf eine Oberflachenlegierungsbildung von Kobalt und Kupfer hin. Es erweist sich, das der Abscheidungs- und Auflosungsprozes nach einiger Zeit des Zykelns reversibel wird. Es werden Struktur und Morphologie von Kobaltfilmen verschiedener Dicke vorgestellt.

Bulletin of the American Physical Society, Mar 17, 2016

Springer Tracts in Modern Physics, 1989

Journal of Physical Chemistry C, Apr 7, 2017

Alloying, de-alloying and reentrant alloying in (sub-)monolayer growth of Ag on Pt(111) 2 Abstrac... more Alloying, de-alloying and reentrant alloying in (sub-)monolayer growth of Ag on Pt(111) 2 Abstract. An in-situ nanoscopic investigation of the prototypical surface alloying system Ag/Pt(111) is reported. The morphology and the structure of the ultrathin Ag-Pt film is studied using Low Energy Electron Microscopy during growth at about 800 K. An amazingly rich dynamic behaviour is uncovered in which stress relieve plays a governing role. Initial growth leads to surface alloying with prolonged and retarded nucleation of ad-islands. Beyond 50% coverage de-alloying proceeds, joined by partial segregation of Pt towards the centre of large islands in violent processes. Upon coalescence the irregularly shaped vacancy clusters are filled by segregating Pt, which then take a compact shape (black spots). As a result at around 85% coverage the strain of the initially pseudo-morphological film is almost completely relieved and Pt-segregation is at its maximum. Further deposition of Ag leads to transient reentrant alloying and recovery of the pseudo-morphological layer. The black spots persist even in/on several layers thick films. Ex-situ atomic force microscopy data confirm that these are constituted by probably amorphous Pt(-rich) structures. The (sub-)monolayer films are very much heterogeneous.

Nanoscience and Technology, 2016

While the default imaging mode in HIM uses secondary electrons, backscattered helium or neon cont... more While the default imaging mode in HIM uses secondary electrons, backscattered helium or neon contains valuable information about the sample composition and structure. In this chapter, we will discuss how backscattered helium can be used to obtain information about buried structures and provide qualitative elemental contrast. The discussion is extended to the use of channeling to increase image quality and obtain crystallographic information. As an example, we demonstrate that the period of a dislocation network in a film only two monolayers thick can be obtained with atomic precision.

Springer Tracts in Modern Physics

Verhandlungen der Deutschen Physikalischen Gesellschaft, 2008

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