From The University of Vienna [Universität Wien] (AT): “Impossible material made possible inside a graphene sandwich”

From The University of Vienna [Universität Wien] (AT)

20. January 2022

Dr. Kimmo Mustonen
Physik Nanostrukturierter Materialien
Universität Wien
1090 – Wien, Boltzmanngasse 5
+43-1-4277-72858
kimmo.mustonen@univie.ac.at

Mag. Alexandra Frey
Pressebüro und stv. Pressesprecherin
Universität Wien
1010 – Wien, Universitätsring 1
+43-1-4277-175 33
+43-664-60277-175 33
alexandra.frey@univie.ac.at

1
A single layer of cuprous iodide encapsulated in between two sheets of graphene (gray atoms). Credit: © 2021 Kimmo Mustonen, Christoph Hofer, and Viera Skákalov.

New results in Advanced Materials

Atoms bind together by sharing electrons. The way this happens depends on the atom types but also on conditions such as temperature and pressure. In two-dimensional (2D) materials such as graphene atoms join along a plane to form structures just one atom thick which leads to fascinating properties determined by quantum mechanics. Researchers at the University of Vienna in collaboration with The Eberhard Karl University of Tübingen [Eberhard Karls Universität Tübingen](DE), and The University of Antwerp [Universiteit Antwerpen](BE) and CY Cergy Paris, together with Danubia NanoTech, have produced a new 2D material made of copper and iodine atoms sandwiched between two graphene sheets. The results were published in the journal Advanced Materials.

The design of new materials allows for either improved efficiency of known applications or totally new applications that were out of reach with the previously existing materials. Indeed, tens of thousands of conventional materials such as metals and their alloys have been identified over the last hundred years. A similar number of possible 2D materials have been predicted to exist, but as of now, only a fraction of them have been produced in experiments. One reason for this is the instability of many of these materials in laboratory conditions.

In the recent study, the researchers synthesized 2D cuprous iodide that was stabilized in a graphene sandwich, as the first example of a material that does not otherwise exist in normal laboratory conditions. The synthesis utilizes the large interlayer spacing of oxidized graphene multilayers, which allows iodine and copper atoms to diffuse into the gap and to grow the new material. The graphene layers here have an important role imposing a high pressure on the sandwiched material that thus becomes stabilized. The resulting sandwich structure is shown in the illustration.

“As so often, when we first saw the new material in our microscopy images, it was a surprise”, says Kimmo Mustonen, the lead author of the study. “It took us quite some time to figure out what the structure precisely was. This enabled us together with Danubia NanoTech company, headed by Viera Skákalová, to design a chemical process for producing it in large scale”, he continues. Understanding the structure was a joint effort of scientists from the Universities of Vienna, Tübingen, Antwerp and CY Cergy Paris. “We had to use several electron microscopy techniques to make sure that we were really seeing a monolayer of copper and iodine and to extract the exact atom positions in 3D, including the latest methods we have recently developed”, the second lead author Christoph Hofer adds.

Following the 2D copper iodide, the researchers have already expanded the synthesis method to produce other new 2D materials. “The method seems to be truly universal, providing access to dozens of new 2D materials. These are truly exciting times!”, Kimmo Mustonen concludes.

See the full article here .

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Stem Education Coalition

The University of Vienna [Universität Wien](AT) is a public university located in Vienna, Austria.It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world. With its long and rich history, the University of Vienna has developed into one of the largest universities in Europe, and also one of the most renowned, especially in the Humanities. It is associated with 21 Nobel prize winners and has been the academic home to many scholars of historical as well as of academic importance.

From the Middle Ages to the Enlightenment

The University was founded on 12 March 1365 by Rudolf IV, Duke of Austria, and his two brothers, Dukes Albert III and Leopold III, hence the additional name “Alma Mater Rudolphina”. After the Charles University in Prague [Univerzita Karlova](CZ) and Jagiellonian University [Uniwersytet Jagielloński](PL), the University of Vienna is the third oldest university in Central Europe and the oldest university in the contemporary German-speaking world; it remains a question of definition as the Charles University in Prague [Univerzita Karlova](CZ) was German-speaking when founded, too.

The University of Vienna was modelled after the University of Paris [Université de Paris](FR). However, Pope Urban V did not ratify the deed of foundation that had been sanctioned by Rudolf IV, specifically in relation to the department of theology. This was presumably due to pressure exerted by Charles IV, Holy Roman Emperor, who wished to avoid competition for the Charles University in Prague. Approval was finally received from the Pope in 1384 and the University of Vienna was granted the status of a full university, including the Faculty of Catholic Theology. The first university building opened in 1385. It grew into the biggest university of the Holy Roman Empire, and during the advent of Humanism in the mid-15th century was home to more than 6,000 students.

In its early years, the university had a partly hierarchical, partly cooperative structure, in which the Rector was at the top, while the students had little say and were settled at the bottom. The Magister and Doctors constituted the four faculties and elected the academic officials from amidst their ranks. The students, but also all other Supposita (university members), were divided into four Academic Nations. Their elected board members, mostly graduates themselves, had the right to elect the Rector. He presided over the Consistory which included procurators of each of the nations and the faculty deans, as well as over the University Assembly, in which all university teachers participated. Complaints or appeals against decisions of faculty by the students had to be brought forward by a Magister or Doctor.

Being considered a Papal Institution, the university suffered quite a setback during the Reformation. In addition, the first Siege of Vienna by Ottoman forces had devastating effects on the city, leading to a sharp decline, with only 30 students enrolled at the lowest point. For King Ferdinand I, this meant that the university should be tied to the church to an even stronger degree, and in 1551 he installed the Jesuit Order there. With the enacting of the Sanctio Pragmatica edict by emperor Ferdinand II in 1623, the Jesuits took over teaching at the theological and philosophical faculty, and thus the university became a stronghold of Catholicism for over 150 years. It was only in the Mid-18th century that Empress Maria Theresa forced the university back under control of the monarchy. Her successor Joseph II helped in the further reform of the university, allowing both Protestants and Jews to enroll as well as introducing German as the compulsory language of instruction.

From the 19th Century Onwards

Big changes were instituted in the wake of the Revolution in 1848, with the Philosophical Faculty being upgraded into equal status as Theology, Law and Medicine. Led by the reforms of Leopold, Count von Thun und Hohenstein, the university was able to achieve a larger degree of academic freedom. The current main building on the Ringstraße was built between 1877 and 1884 by Heinrich von Ferstel. The previous main building was located close to the Stuben Gate (Stubentor) on Iganz Seipel Square, current home of the old University Church (Universitätskirche) and the Austrian Academy of Sciences [Österreichische Akademie der Wissenschaften(AT). Women were admitted as full students from 1897, although their studies were limited to Philosophy. The remaining departments gradually followed suit, although with considerable delay: Medicine in 1900, Law in 1919, Protestant Theology in 1923 and finally Roman Catholic Theology in 1946. Ten years after the admission of the first female students, Elise Richter became the first woman to receive habilitation, becoming professor of Romance Languages in 1907; she was also the first female distinguished professor.

In the late 1920s, the university was in steady turmoil because of anti-democratic and anti-Semitic activity by parts of the student body. Professor Moritz Schlick was killed by a former student while ascending the steps of the University for a class. His murderer was later released by the Nazi Regime. Following the Anschluss, the annexation of Austria into Greater Germany by the Nazi regime, in 1938 the University of Vienna was reformed under political aspects and a huge number of teachers and students were dismissed for political and “racial” reasons. In April 1945, the then 22-year-old Kurt Schubert, later acknowledged doyen of Judaic Studies at the University of Vienna, was permitted by the Soviet occupation forces to open the university again for teaching, which is why he is regarded as the unofficial first rector in the post-war period. On 25 April 1945, however, the constitutional lawyer Ludwig Adamovich senior was elected as official rector of the University of Vienna. A large degree of participation by students and university staff was realized in 1975, however the University Reforms of 1993 and 2002 largely re-established the professors as the main decision makers. However, also as part of the last reform, the university after more than 250 years being largely under governmental control, finally regained its full legal capacity. The number of faculties and centers was increased to 18, and the whole of the medical faculty separated into the new Medical University of Vienna [Medizinische Universität Wien](AT).