Discovery led by University of Minnesota researchers could have a big impact in the semiconductor industry
A new experimental discovery, led by researchers at the University of Minnesota, demonstrates that the chemical element ruthenium (Ru) is the fourth single element to have unique magnetic properties at room temperature. The discovery could be used to improve sensors, devices in the computer memory and logic industry, or other devices using magnetic materials.
This schematic illustrates how a tetragonal phase of Ru has been forced using ultra thin film growth methods.
Credit: University of Minnesota, Quarterman et al, Nature Communications
The use of ferromagnetism, or the basic mechanism by which certain materials (such as iron) form permanent magnets or are attracted to magnets, reaches back as far as ancient times when lodestone was used for navigation. Since then only three elements on the periodic table have been found to be ferromagnetic at room temperature--iron (Fe), cobalt (Co), and nickel (Ni). The rare earth element gadolinium (Gd) nearly misses by only 8 degrees Celsius.
Magnetic materials are very important in industry and modern technology and have been used for fundamental studies and in many everyday applications such as sensors, electric motors, generators, hard disk media, and most recently spintronic memories.
As thin film growth has improved over the past few decades, so has the ability to control the structure of crystal lattices--or even force structures that are impossible in nature. This new study demonstrates that Ru can be the fourth single element ferromagnetic material by using ultra-thin films to force the ferromagnetic phase.
The details of their work are published in the most recent issue of Nature Communications. The lead author of the paper is a recent University of Minnesota Ph.D. graduate Patrick Quarterman, who is a National Research Council (NRC) postdoctoral fellow at the National Institute of Standards and Technology (NIST).
"Magnetism is always amazing. It proves itself again. We are excited and grateful to be the first group to experimentally demonstrate and add the fourth ferromagnetic element at room temperature to the periodic table," said University of Minnesota Robert F. Hartmann professor of electrical and computer engineering Jian-Ping Wang, the corresponding author for the paper and Quarterman's advisor.
"This is an exciting but hard problem. It took us about two years to find a right way to grow this material and validate it. This work will trigger magnetic research community to look into fundamental aspects of magnetism for many well-known elements," Wang added.
Other members of the team also stressed the importance of this work.
"The ability to manipulate and characterize matter at the atomic scale is the cornerstone of modern information technology," said study co-author Paul Voyles, a Beckwith-Bascom Professor and Chair of the Department of Materials Science and Engineering at the University of Wisconsin-Madison. "Our collaboration with University of Minnesota Professor Wang's group shows that these tools can find new things even in the simplest systems, consisting of a just a single element."
Industry partners agree that collaboration is key to innovation
"Intel is pleased with the long-term research collaboration it has with the University of Minnesota and C-SPIN [Center for Spintronic Materials, Interfaces, and Novel Architectures], said Ian A. Young, Senior Fellow and Director at Intel Corporation. "We are excited to share these developments enabled by exploring the behavior of quantum effects in materials, which may provide insights for innovative energy efficient logic and memory devices." Other industry leaders agree that this discovery will have an impact on the semiconductor industry.
"Spintronic devices are of rapidly increasing importance to the semiconductor industry," said Todd Younkin, the director of Defense Advanced Research Projects Agency (DARPA)-sponsored consortia at Semiconductor Research Corporation (SRC). "Fundamental advances in our understanding of magnetic materials, such as those demonstrated in this study by Professor Wang and his team, is critical to realizing continued breakthroughs in computing performance and efficiency."
Novel technologies require novel materials
Magnetic recording is still the dominant player in data storage technology, but magnetic based random-access memory and computing is beginning to take its place. These magnetic memories and logic devices put additional constraints on the magnetic materials, where data is stored and computed, compared to traditional hard disk media magnetic materials. This push for novel materials has led to renewed interest in attempts to realize predictions which show that under the right conditions, non-ferromagnetic materials, such as Ru, palladium (Pd) and osmium (Os) can become ferromagnetic.
Building upon the established theoretical predictions, researchers at the University of Minnesota used seed layer engineering to force the tetragonal phase of Ru, which prefers to have a hexagonal configuration, and observed the first instance of ferromagnetism in a single element at room temperature. The crystal structure and magnetic properties were extensively characterized by collaborating with the University of Minnesota's Characterization Facility and colleagues at the University of Wisconsin.
The researchers said this study opens the door to fundamental studies of this new ferromagnetic Ru. From an application perspective, Ru is interesting because it is resistant to oxidation, and additional theoretical predictions claim it has a high thermal stability--a vital requirement for scaling magnetic memories. Examination of this high thermal stability is the focus of ongoing research at the University of Minnesota.
In addition to Quarterman, Wang, and Voyles, researchers involved in this study include Javier Garcia-Barriocanal from the University of Minnesota Characterization Facility; Yang Lv from the University of Minnesota Department of Electrical and Computer Engineering; Mahendra DC from the University of Minnesota School of Physics and Astronomy; Sasikanth Manipatruni, Demitri Nikonov, and Ian Yang from Intel Components Research; and Congi Sun from the University of Wisconsin Department of Materials Science and Engineering.
This research was funded by the Center for Spintronic Materials, Interfaces and Novel Architectures (C-SPIN) at the University of Minnesota, the University of Minnesota Distinguished Doctoral Fellowship, and the National Science Foundation (NSF) through the NSF-funded Materials Research Science and Engineering Center at the University of Minnesota.
To read the full paper entitled "Demonstration of Ru as the 4th ferromagnetic element at room temperature," by Quarterman et al, visit the Nature Communications website.
Lacey Nygard | EurekAlert!
Quantum bugs, meet your new swatter
20.08.2018 | Rice University
Metamolds: Molding a mold
20.08.2018 | Institute of Science and Technology Austria
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
21.08.2018 | Power and Electrical Engineering
21.08.2018 | Life Sciences
21.08.2018 | Medical Engineering