From The DOE’s Brookhaven National Laboratory
6.26.24
Laura Mgrdichian-West
lmgrdichi@bnl.gov
Abdullah Al-Mahboob (Kevin Coughlin/Brookhaven National Laboratory)
Abdullah Al-Mahboob is a scientist in the Interface Science and Catalysis group at the Center for Functional Nanomaterials (CFN) [below] and uses the resources of the National Synchrotron Light Source II [below]; both are U.S. Department of Energy (DOE) Office of Science user facilities at DOE’s Brookhaven National Laboratory. A longtime CFN user prior to joining the CFN staff in 2022, Al-Mahboob is using cutting-edge tools at both facilities to study the properties of ultra-thin layered materials with interesting electronic and optical properties.
What kind of materials do you study at CFN?
One of my goals as a CFN staff scientist is to develop new 2D quantum materials. I study transition metal dichalcogenides (TMDs), which are 2D quantum materials that consist of a transition metal layer, such as molybdenum or tungsten, between two layers of a chalcogen, such as sulfur or selenium. This configuration is called a heterostructure and is essentially 2D because the layers are atomically thin. These 2D materials can behave in very interesting and potentially useful ways.
I am particularly interested in how energy and charge transfer between the layers. How is this affected by the spacing between the layers? What happens when they are excited with light? TMDs are a playground for exploring new physics, such as new quantum optical properties. They could have an important role in new technologies.
What kind of new behaviors can result from this configuration?
One thing we have been studying, in a collaboration with colleagues at the University of Warsaw in Poland, is what happens when a material with a small energy band gap is stacked with a material that has a large energy band gap. The band gap defines how much energy is needed for valence electrons to become conduction electrons.
In this case, energy can transfer from the lower-energy band gap material to the higher-energy band gap material when the system is excited. For example, in certain conditions, we see that the lower-energy band gap material can absorb light and transfer it to the other material. When you have atomically thin layers and increase the distance between the layers within a range of, typically, just a few nanometers, the energy transfer first increases and then starts to decrease. This is a new phenomenon that we are trying to understand, such as by trying out different combinations of 2D materials and looking at how their structures affect the energy transfer.
What research tools do you use?
My expertise is in spectro-microscopy tools, such as electron microscopy and photo-electron microscopy, which are available at CFN. I also rely on low energy electron microscopy and X-ray photoemission electron microscopy, which are two techniques available at the NSLS-II Electron Spectro-Microscopy (ESM) beamline. By combining the methods available at the two facilities, we can study our samples’ properties in real time.
I also use CFN’s Quantum Material Press, or QPress, which is a robotic, automated system for creating heterostructures. Previously, we had to create samples by using Scotch tape to manually “lift” layers off a bulk sample. This was a difficult process, and you might make many samples and only get one that is right. With the QPress, the process is much quicker, and the samples yielded are of much higher quality. I can get my samples prepared in a day, versus a few days. The QPress provides you with the ability to control the rotation and tilt of the layers, as well.
What else are you studying right now?
Currently, I am developing new phases of 2D silicon materials, which is a separate project from my TMD research. Ultimately, I would like to combine existing silicon technologies with new 2D silicon-based materials to yield new technologies.
Another collaboration we are doing with the University of Warsaw is studying samples fabricated from TMDs that are bilayer materials. We are seeing that there is immediate charge transfer between the layers. We are also looking at how the substrate affects the charge transfer. For example, one substrate we use is sapphire because TMDs can be grown epitaxially on sapphire, which means that the TMD layer grows in a way that is directed by the molecular structure of the sapphire.
Other substrates that we are experimenting with are copper, ruthenium, and quartz. Depending on what kind of measurements we want to do, we pick the substrate accordingly. Quartz, for example, is optically inert, meaning it doesn’t change the properties of incoming light. That makes it appropriate for optical experiments.
What is a typical week like for you at CFN?
A few days a week, I have meetings with users. I also have students working with me, so I have to make time for them. Otherwise, it is a relaxed schedule. However, as a scientist at a user facility, I cannot use the instruments whenever I want. I have to submit and use my own user proposal time, or I can come in on the weekend or at night when we need extra time beyond what our proposal gives us. Sometimes, I even work throughout the night. I try to use the tools as much as possible.
See the full article here .
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One of ten national laboratories overseen and primarily funded by the The DOE Office of Science, The DOE’s Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
Research at BNL specializes in nuclear and high energy physics, energy science and technology, environmental and bioscience, nanoscience and national security. The 5300 acre campus contains several large research facilities, including the Relativistic Heavy Ion Collider [below] and National Synchrotron Light Source II [below]. A number of Nobel prizes have been awarded for work conducted at Brookhaven lab.
BNL is staffed by approximately 2,750 scientists, engineers, technicians, and support personnel, and hosts 4,000 guest investigators every year. The laboratory has its own police station, fire department, and ZIP code (11973). In total, the lab spans a 5,265-acre (21 km^2) area that is mostly coterminous with the hamlet of Upton, New York. BNL is served by a rail spur operated as-needed by the New York and Atlantic Railway. Co-located with the laboratory is the Upton, New York, forecast office of the National Weather Service.
Major programs
Although originally conceived as a nuclear research facility, Brookhaven Lab’s mission has greatly expanded. Its foci are now:
Nuclear and high-energy physics
Physics and chemistry of materials
Environmental and climate research
Nanomaterials
Energy research
Nonproliferation
Structural biology
Accelerator physics
Operation
Brookhaven National Lab was originally owned by the Atomic Energy Commission and is now owned by that agency’s successor, the United States Department of Energy (DOE). DOE subcontracts the research and operation to universities and research organizations. It is currently operated by Brookhaven Science Associates LLC, which is an equal partnership of Stony Brook University and Battelle Memorial Institute. From 1947 to 1998, it was operated by Associated Universities, Inc. (AUI), but AUI lost its contract in the wake of two incidents: a 1994 fire at the facility’s high-beam flux reactor that exposed several workers to radiation and reports in 1997 of a tritium leak into the groundwater of the Long Island Central Pine Barrens on which the facility sits.
Foundations
Following World War II, the US Atomic Energy Commission was created to support government-sponsored peacetime research on atomic energy. The effort to build a nuclear reactor in the American northeast was fostered largely by physicists Isidor Isaac Rabi and Norman Foster Ramsey Jr., who during the war witnessed many of their colleagues at Columbia University leave for new remote research sites following the departure of the Manhattan Project from its campus. Their effort to house this reactor near New York City was rivalled by a similar effort at the Massachusetts Institute of Technology to have a facility near Boston, Massachusetts. Involvement was quickly solicited from representatives of northeastern universities to the south and west of New York City such that this city would be at their geographic center. In March 1946 a nonprofit corporation was established that consisted of representatives from nine major research universities — Columbia University, Cornell University, Harvard University, Johns Hopkins University, Massachusetts Institute of Technology, Princeton University, University of Pennsylvania, University of Rochester, and Yale University.
Out of 17 considered sites in the Boston-Washington corridor, Camp Upton on Long Island was eventually chosen as the most suitable in consideration of space, transportation, and availability. The camp had been a training center from the US Army during both World War I and World War II. After the latter war, Camp Upton was deemed no longer necessary and became available for reuse. A plan was conceived to convert the military camp into a research facility.
On March 21, 1947, the Camp Upton site was officially transferred from the U.S. War Department to the new U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE).
Research and facilities
Reactor history
In 1947 construction began on the first nuclear reactor at Brookhaven, the Brookhaven Graphite Research Reactor. This reactor, which opened in 1950, was the first reactor to be constructed in the United States after World War II. The High Flux Beam Reactor operated from 1965 to 1999. In 1959 Brookhaven built the first US reactor specifically tailored to medical research, the Brookhaven Medical Research Reactor, which operated until 2000.
Accelerator history
In 1952 Brookhaven began using its first particle accelerator, the Cosmotron. At the time the Cosmotron was the world’s highest energy accelerator, being the first to impart more than 1 GeV of energy to a particle.
The Cosmotron was retired in 1966, after it was superseded in 1960 by the new Alternating Gradient Synchrotron (AGS).
BNL Alternating Gradient Synchrotron (AGS).
The AGS was used in research that resulted in 3 Nobel prizes, including the discovery of the muon neutrino, the charm quark, and CP violation.
In 1970 in BNL started the ISABELLE project to develop and build two proton intersecting storage rings.
The groundbreaking for the project was in October 1978. In 1981, with the tunnel for the accelerator already excavated, problems with the superconducting magnets needed for the ISABELLE accelerator brought the project to a halt, and the project was eventually cancelled in 1983.
After ISABELLE’S cancellation, physicist at BNL proposed that the excavated tunnel and parts of the magnet assembly be used in another accelerator. In 1984 the first proposal for the accelerator now known as the Relativistic Heavy Ion Collider (RHIC)[below] was put forward. The construction got funded in 1991 and RHIC has been operational since 2000. One of the world’s only two operating heavy-ion colliders, RHIC is as of 2010 the second-highest-energy collider after the Large Hadron Collider (CH). RHIC is housed in a tunnel 2.4 miles (3.9 km) long and is visible from space.
On January 9, 2020, it was announced by Paul Dabbar, undersecretary of the US Department of Energy Office of Science, that the BNL eRHIC design has been selected over the conceptual design put forward by DOE’s Thomas Jefferson National Accelerator Facility [Jlab] as the future Electron–ion collider (EIC)
In addition to the site selection, it was announced that the BNL EIC had acquired CD-0 from the Department of Energy. BNL’s eRHIC design proposes upgrading the existing Relativistic Heavy Ion Collider, which collides beams light to heavy ions including polarized protons, with a polarized electron facility, to be housed in the same tunnel.
Other discoveries
In 1958, Brookhaven scientists created one of the world’s first video games, Tennis for Two. In 1968 Brookhaven scientists patented Maglev, a transportation technology that utilizes magnetic levitation.
Major facilities
Relativistic Heavy Ion Collider (RHIC), which was designed to research quark–gluon plasma and the sources of proton spin. Until 2009 it was the world’s most powerful heavy ion collider. It is the only collider of spin-polarized protons.
Center for Functional Nanomaterials (CFN), used for the study of nanoscale materials.
BNL National Synchrotron Light Source II, Brookhaven’s newest user facility, opened in 2015 to replace the National Synchrotron Light Source (NSLS), which had operated for 30 years. NSLS was involved in the work that won the 2003 and 2009 Nobel Prize in Chemistry.
Alternating Gradient Synchrotron, a particle accelerator that was used in three of the lab’s Nobel prizes.
Accelerator Test Facility, generates, accelerates and monitors particle beams.
Tandem Van de Graaff, once the world’s largest electrostatic accelerator.
Computational Science resources, including access to a massively parallel Blue Gene series supercomputer that is among the fastest in the world for scientific research, run jointly by Brookhaven National Laboratory and Stony Brook University-SUNY.
Interdisciplinary Science Building, with unique laboratories for studying high-temperature superconductors and other materials important for addressing energy challenges.
NASA Space Radiation Laboratory, where scientists use beams of ions to simulate cosmic rays and assess the risks of space radiation to human space travelers and equipment.
Off-site contributions
It is a contributing partner to the ATLAS experiment, one of the four detectors located at the The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organization européenne pour la recherche nucléaire] [Europäische Organization für Kernforschung](CH)[CERN] Large Hadron Collider(LHC). Credit: CERN.
It is currently operating at The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organization européenne pour la recherche nucléaire] [Europäische Organization für Kernforschung](CH) [CERN] near Geneva, Switzerland.
Brookhaven was also responsible for the design of Spallation Neutron Source at the DOE’s Oak Ridge National Laboratory, Tennessee.
Brookhaven plays a role in a range of neutrino research projects around the world, including the Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China.
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