Brown University researchers and collaborators from Tsinghua University in China have shown that nanoclusters made from boron and lanthanide elements form highly stable and symmetric structures with interesting magnetic properties.
The findings, published in Proceedings of the National Academy of Sciences on Monday, July 9, suggest that these nanoclusters may be useful as molecular magnets or assembled into magnetic nanowires.
The research also helps shed light on the structure and chemical bonding of bulk boron lanthanides, which may help in engineering new boride materials.
"Boron lanthanides are an important class of materials used in electronics and other applications, but nanoclusters of boron lanthanides have not been studied," said Lai-Sheng Wang, a professor of chemistry at Brown and senior author of a paper describing the work. "We have just started to investigate these nanoclusters, and here we show that they can have an interesting 'inverse sandwich' structure with the right combination of boron and lanthanide atoms."
The structure -- a ring of bonded boron atoms with a single lanthanide atom bonded to each side -- emerged in clusters made from eight boron atoms and two atoms of either lanthanum or praseodymium (both members of the lanthanide group on the periodic table).
Sandwich structures -- complexes in which two planar aromatic hydrocarbon molecules surround a single metal atom -- are well known in chemistry and their discovery earned a Nobel Prize in 1973. Inverse sandwich structures are known to form in uranium-organic molecular complexes, Wang says, but this is the first time the structure has been seen in boron lanthanides.
Wang's lab used a technique called photoelectron spectroscopy to study nanoclusters made of different chemical elements. The technique involves zapping atomic clusters with a high-powered laser. Each zap knocks an electron out of the cluster.
By measuring the kinetic energy of those freed electrons, researchers can understand how the atoms in a cluster are bound together and infer the cluster's physical structure. To find the structures, Wang compared the photoelectron spectra with theoretical calculations done by quantum chemist Professor Jun Li and his students from Tsinghua.
"We found that clusters made of eight boron and two lanthanide atoms are highly symmetric as inferred from their simple spectral patterns," Wang said. "In chemistry, whenever we find something that's highly symmetric it's very exciting."
That symmetry is produced, Wang said, by the nature of the chemical bonds that hold the structure together. The nature of those bonds also makes the clusters highly magnetic. That could make them useful for in nano-electronics applications or elsewhere.
The research also helps to shed light on bulk borides, Wang says.
"It gives us a new way of understanding the bonding and structure of boride materials," he said. "By studying small units, we can gain insight into the bulk system, and I think we have gained some of that insight here."
Wang's co-authors on the study were Wan-Lu Li, Teng-Teng Chen, Deng-Hui Xing, Xin Chen and Jun Li. The research was supported by the U.S. National Science Foundation (CHE-1763380) and the National Natural Science Foundation of China.
Novel sensors could enable smarter textiles
17.08.2018 | University of Delaware
Quantum material is promising 'ion conductor' for research, new technologies
17.08.2018 | Purdue University
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
20.08.2018 | Life Sciences
20.08.2018 | Information Technology
20.08.2018 | Power and Electrical Engineering