Researchers of the University of Basel have developed a new method with which individual isolated molecules can be studied precisely – without destroying the molecule or even influencing its quantum state. This highly sensitive technique for probing molecules is widely applicable and paves ... more
2D materials: arrangement of atoms measured in silicene
Silicene consists of a single layer of silicon atoms. In contrast to the ultra-flat material graphene, which is made of carbon, silicene shows surface irregularities that influence its electronic properties. Now, physicists from the University of Basel have been able to precisely determine this corrugated structure. As they report in the journal PNAS, their method is also suitable for analyzing other two-dimensional materials.
A low-temperature atomic force microscope with a single carbon atom at the tip allows quantitative measurement of forces between sample and tip. With two-dimensional silicon (silicene), surface buckling can be quantitatively determined. (Image: University of Basel, Department of Physics)
Since the experimental production of graphene, two-dimensional materials have been at the heart of materials research. Similar to carbon, a single layer of honeycombed atoms can be made from silicon. This material, known as silicene, has an atomic roughness, in contrast to graphene, since some atoms are at a higher level than others.
Silicene not completely flat
Now, the research team, led by Professor Ernst Meyer of the Department of Physics and the Swiss Nanoscience Institute of the University of Basel, has succeeded in quantitatively representing these tiny height differences and detecting the different arrangement of atoms moving in a range of less than one angstrom – that is, less than a 10-millionth of a millimeter.
“We use low-temperature atomic force microscopy with a carbon monoxide tip,” explains Dr. Rémy Pawlak, who played a leading role in the experiments. Force spectroscopy allows the quantitative determination of forces between the sample and the tip. Thus, the height in relation to the surface can be detected and individual atoms can be chemically identified. The measurements show excellent agreement with simulations carried out by partners at the Instituto de Ciencia de Materiales de Madrid (ICMM).
Different electronic properties
This unevenness, known as buckling, influences the electronic properties of the material. Unlike graphene, which is known to be an excellent conductor, on a silver surface silicene behaves more like a semiconductor. “In silicene, the perfect honeycomb structure is disrupted. This is not necessarily a disadvantage, as it could lead to the emergence of interesting quantum phenomena, such as the quantum spin hall effect,” says Meyer.
The method developed by the researchers in Basel offers new insights into the world of two-dimensional materials and the relationship between structure and electronic properties.
- 2D materials
- Universität Basel
- low-temperature ato…
The University of Basel is part of the global search for a drug to fight the rampant coronavirus. Researchers in the Computational Pharmacy group have so far virtually tested almost 700 million substances, targeting a specific site on the virus – with the aim of inhibiting its multiplicatio ... more
Protein variations that result from the process of alternative splicing control the identity and function of nerve cells in the brain. This allows organisms to build a highly complex neuronal network with only a limited number of genes. The study describing a detailed map of neuronal splici ... more
Zooming into a nuclear pore complex using a high-speed atomic force microscope reveals the selectivity barrier that filters the traffic of molecules passing between the cytoplasm and nucleus in eukaryotic cells. This is comprised of intrinsically disordered proteins known as FG Nucleoporins ... more
- 1New Indication of a Link Between Alzheimer’s and Diabetes
- 2Click... Resistant bacteria caught in the act!
- 3Nanosafety research without animal experiments
- 4The relationship of proteins
- 5Could the blood of COVID-19 patients be used to predict disease progression?
- 6DKSH extends partnership with Bruker in China
- 7Detecting antibodies with glowing proteins, thread and a smartphone
- 8RNA structures by the thousands
- 9Developing new techniques to improve atomic force microscopy
- 10Snapshot of exploding oxygen