Try as they might, ancient alchemists could never turn lead into gold. Neither can the members of the Novel Materials group at the U.S. Department of Energy’s Ames Laboratory. But these physicists do have a way with materials, and they can get them to do some pretty amazing things.
Drs. Paul Canfield and Sergey Bud’ko and their Iowa State University Department of Physics and Astronomy graduate student, Shuang Jia, have discovered a new family of zinc compounds that can be tuned, or manipulated, to take on some of the physical properties and behavior of other materials, ranging from plain old copper to more exotic elements like palladium, to even more complex electronic and magnetic compounds that are on, as Canfield said, “the hairy edge” of becoming magnetic (or even superconducting).
Their versatility makes the new zinc compounds ideal for basic research efforts to observe and learn more about the origins of phenomena such as magnetism. Basic research is the building block. Once scientists understand how these materials work, products and/or processes can follow.In addition, zinc is very cheap. In 1982, the U.S.Mint switched the composition of the penny to 97.5 percent zinc and only 2.5 percent copper. In a similar manner, this class of compounds is over 85 percent zinc. If technological applications can be found, these compounds will literally only cost pennies to make.
“We can make compounds for up to 10 transition metals, and for each of those we can include between seven and 14 rare earths,” said Canfield. “So that’s between 70 and 140 compounds.”
One of the compounds the researchers made, YFe2Zn20 (Y=yttrium, Fe=iron, Zn=zinc), turned out to be even closer to being ferromagnetic than palladium, a nearly ferromagnetic material that scientists have traditionally studied to better understand magnetism.
Canfield describes palladium as a “runner-up” in terms of band magnetism – the magnetism of the common metals like iron, cobalt or nickel. These metals become ferromagnetic at such high temperatures that it’s difficult to study them in detail, so palladium is the next-best option. In addition, palladium acts as a “before” picture to their “after” in terms of ferromagnetism.
“The problem is that as an element, palladium is a little hard to tune,” said Canfield. “There is one palladium site, and it’s not that versatile. For basic research as well as possible applied materials, you want compounds that allow for the manipulation of their properties. We can tune the rare earth-iron(2)-zinc(20) so we’re able to push these compounds even closer to ferromagnetism and try to understand the consequences of this,” he explained.
Canfield, Bud’ko, and Jia have also tuned the zinc(20) compounds by substituting on the rare earth side, for example, by exchanging yttrium for gadolinium. Canfield explained, “It’s like having a panicky crowd and someone yelling, ‘Quick, run this way!’ All of a sudden, everyone runs that way. That’s what adding the gadolinium does – the compound just suddenly goes ferromagnetic at an unexpectedly high temperature.”
The researchers can also tune the zinc(20) compounds by “playing” with the transition metal site. “By substituting cobalt for iron, we can back this material off,” said Canfield. The yttrium-cobalt-zinc(20) is about as ferromagnetic as copper, which means it’s not. So we can calm the crowd down a little and see what happens.”
The remarkable tunability of the new family of zinc(20) compounds is allowing Canfield, Bud’ko and Jia to approach the ferromagnetic transition point from where they hope to achieve another ambition – pushing the material to become ferromagnetic at very low temperatures by tweaking and tuning. “If we could do that,” said Canfield, “then we could actually witness the birth of this type of small moment ferromagnetism – instead of just before and after pictures, we could watch the whole film.”
As they continue to work toward that goal, Canfield and Bud’ko stress the importance of being able to do materials research at a DOE lab. “There are many different skills and resources available to draw on,” said Canfield. “Experimentally, it’s very important to have design, synthesis and characterization very tightly linked. “You need to have your intrepid band of explorers able to investigate and contribute. Let me give you two extreme examples. First, being in Ames gives us access to the world’s highest purity rare earth elements. We need these to explore the effects of substitution on the rare earth site. On the other extreme, in these nearly ferromagnetic materials, band structure calculations have been very important, and being able to tie into the Ames Lab band structure expertise of German Samolyuk has been incredibly useful in helping us understand it and trying to figure out where the next moves are.”
The DOE Office of Science Basic Energy Sciences Office funded the work described above on the new family of zinc compounds.
Ames Laboratory, celebrating its 60th anniversary in 2007, is operated for the Department of Energy by Iowa State University. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and the synthesis and study of new materials.
Saren Johnston | EurekAlert!
Data storage using individual molecules
17.12.2018 | Universität Basel
Formed to Meet Customers’ Needs – New Laser Beams for Glass Processing
17.12.2018 | Fraunhofer-Institut für Lasertechnik ILT
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
17.12.2018 | Physics and Astronomy
17.12.2018 | Architecture and Construction
17.12.2018 | Life Sciences