Thursday , June 17 2021

Use a microscope like a shovel? Researchers dig it

<a rel = "lightbox" href = "" title = "TAFM de BiFeO3 / SrRuO3 / DyScO3 malicious film heterostructure. Credit: Proceedings of the National Academy of Sciences (2019). DOI: 10.1073 / pnas.1806074116 ">
Use a microscope like a shovel? Researchers dig it

TAFM of BiFeO3 / SrRuO3 / DyScO3 thin film heterostructure. Credit: Proceedings of the National Academy of Sciences (2019). DOI: 10.1073 / pnas.1806074116

Using a familiar tool in a way that it never intended to be used, opens a whole new method of researching materials, inform UConn researchers in Proceedings of the National Academy of Science. Their specific finding could ever create much more energetic computers, but the new technique itself could open new discoveries in a wide range of fabrics.

Atomic strong microscopes (AFM) drag an ultra acute end across materials, sometimes so close but never affecting the surface. The tip may feel where the surface is, detecting electrical and magnetic forces produced by the material. By going to cross it, the researcher can take care of the surface properties of material as well as an investigator putting a method across the country to map the territory. AFMs can give a map of holes, protrusions and properties of material at scale thousands of times smaller than salt grain.

AFM are designed to investigate surfaces. Most of the time, the user tries very hard not to actually bump the material with the tip, because it could damage the surface of the material. But sometimes it happens. A few years ago, a graduate student Yasemin Kutes and Justin Luria, a postdoc, studying solar cells in the scientific material and engineering professor of the laboratory Brian Huey, accidentally hid into his specimen. Initially believing that it was a fierce error, they realized that the properties of the material looked different when Codes hit the top of the AFM in the ditch which she accidentally dug.

Kutes and Luria did not pursue it. But another graduate student, James Steffes, was inspired to look closer to the idea. What would happen if you had used the top of AFM as a chisel and dug into material, did it marvel? Could it be possible to detect the electrical and magnetic properties of a layer by means of a layer, to construct a 3-D image of the properties of the material as it mapped the surface in 2-D? And would the properties look in any different depth within the material?

They answer the answers, Steffes, Huey, and their colleagues PNAS, yes and yes. They dug in a sample of bismuth ferrita (BiFeO3), which is a room with a multifier temperature. Multifunction are materials that can have many electrical or magnetic properties at the same time. For example, bismuth ferrito is both antiferromagnetic – it corresponds to magnetic fields, but generally does not show a north or south magnetic polar and a ferroelectric, which means it has a powerless electric polarization. Such ferroelectric materials usually consist of small sections, called domains. Every domain is like a pool of batteries that all have their positive terminals aligned in the same direction. The masses on both sides of this rule will be noted in another direction. They are very valuable for computer memory, because the computer can fly the domains, & # 39; on the material, using magnetic or electric fields.

When scientific materials read or write information about a bismuth fragment, they usually can only see what is happening on the surface. But they would love to know what is happening under the surface – if this was understood, it might be possible to engineer the material into more efficient computers that work faster and use less energy than those available today. This could make a big difference in the total energy consumption of the company – and 5 percent of the total electricity consumed in the United States are running computers.

In order to find out, Steffes, Huey, and the rest of the team used an AFM type for a little digging with a bismuth ferrite film and emitting the inside, a piece per piece. They found that they can map the individual domains everywhere, showing patterns and properties that do not always appear on the surface. Sometimes a domain was narrowed until it disappeared or split into the form of y, or merged with another domain. No one had ever seen inside the material. It was revealed, like looking at a 3-D-CT skin of a bone when you could only read 2-ray rays before.

"Worldwide, there are already 30,000 AFM installed. A big fraction of those attempts [3-D mapping with] AFM in 2019, as our community realizes that they have just scraped the surface all the time, "Huey predicted. He also thinks that more workers will buy AFMs now if 3-D mapping proves to work for their materials, and some microscopic manufacturers will be Begin to draw AFMs specifically for 3-D scanning.

Steffes later graduated from UConn with his Ph.D. and now works at a GlobalFoundries, a computer chip manufacturer. Investigators at Intel, muratas and elsewhere are also interested in what the group has learned about bismuth ferrita since they are looking for new materials to make the next generation of computer chips. Meanwhile, meanwhile, now use AFMs to dig in all kinds of materials, from concrete to bone to host of computer components.

"Working with academic companies and companies, we can use our new understanding to understand how best engineer these materials are to use less energy, optimize their performance and improve their reliability and life – these are examples of how materials scientists are trying to do every day, "Huey says.

Explore further:
Relationship between the structure and magnetic properties of ceramics

More information:
James J. Steffes et al, Scale of ferroelectricity in BiFeO3 by tomography atomic force microscopy, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073 / pnas.1806074116

Reference of a newspaper:
Proceedings of the National Academy of Sciences

Brindita by:
University of Connecticut

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