ASU is home to researchers at the forefront of material science, pushing boundaries with innovative techniques. These methods are not only advancing the understanding of matter but also driving the development of practical applications in areas like semiconductors and biology.
"(These techniques)are part of a new area of development for understanding materials," said Jingyue Liu, a senior global futures scientist with the Global Futures Scientists and Scholars Network.
These new techniques using X-rays can be applied for material translation, which was previously based on assumptions rather than experimental evidence.
Overcoming the limitations of current techniques
For decades, tools like electron microscopy have been foundational in material science, offering an unparalleled ability to visualize matter at the atomic scale. Electron microscopy uses a beam of electrons to image the structure of microscopic samples.
However, electron microscopy is limited when dealing with diverse environments and large sample sizes.
“The electron microscopy technique has been developed at ASU (for) at least 40, more than 40 years,” Liu said. “The limitation is the electron microscope, you need a vacuum.”
The requirement for a vacuum imposes significant restrictions, particularly for materials that must remain hydrated or in their natural state.
Similarly, dynamic light scattering, a method often used to analyze particle size distribution in solutions, faces its own set of challenges.
"Dynamic light scattering ... provides particle size distribution, but it has limitations because light wavelengths are relatively long," Liu said.
These longer wavelengths restrict the ability to resolve smaller particles accurately.
By overcoming these constraints, newer methods are enabling researchers to explore previously inaccessible aspects of material behavior and structure.
X-ray techniques: A game changer
X-ray techniques have emerged as transformative tools in material science, providing unprecedented insights into the structure and behavior of materials.
“For all the research that I was doing, what was important was to understand the nature of the active sites," said Tijana Rajh, the director for the School of Molecular Sciences. "The only technique that can give you some idea about the environment, what their structure is, what their electronics is, what the properties are, are actually X-ray techniques."
Rajh emphasized the versatility of these tools. Advancements like nanoprobe enhancement at X-ray facilities have allowed for highly targeted investigations of solid and soft materials.
“What has been developed ... is this nanoprobe, which means X-ray, that is examining only the micron, submicron region of the material,” Rajh said.
The precision of these techniques has opened doors to studying materials at a level previously unattainable.
"We could focus the X-ray exactly on the corner, on the one facet, when we knew exactly what is the edge, and then follow how that changes when we bind CO2 and when we shine a light on it," Rajh said.
These capabilities provide researchers with unparalleled control in observing dynamic processes and structural changes in real-time.
In different application, the cutting-edge technique of X-ray Photon Correlation Spectroscopy is one of the most impactful developments in this area. While nanoprobes use both probes and X-rays, XPCS uses alternating beams of X-rays to probe.
"This new development targets understanding small particles, especially in liquid environments," Liu said.
Applications in real-world challenges
The practical applications of these X-ray techniques are profound, finding new materials to improve existing products, like semiconductors.
Semiconductors are materials that control the flow of electricity in electronic products. New X-ray techniques are helping researchers find more optimal materials, like amorphous silicon, to make a new generation of semiconductors.
"We do not understand exactly why amorphous silicon is so good," Rajh said. "It would be great to have better understanding, and then we can design maybe new semiconductors that are also amorphous."
Liu emphasized the far-reaching implications of these advancements.
"That's where exactly the ultimate physics, the benefit for (the) economy and the society directly linked," Liu said.
Advanced techniques are also enabling researchers to study the dynamic behavior of organic matter.
"These first steps of change are critical for us to understand how things work," Rajh said. "So when you could monitor in biology, how, for example, when ATP binds, how it changes the structure, how the structure changes electronic structures because you can image that with X-ray in the same time."
An interdisciplinary approach at ASU
Jason Khoury, assistant professor in the School of Molecular Sciences and solid-state chemist, highlighted the role of X-ray diffraction in advancing research of both material sciences and chemistry.
"Laboratory X-ray diffraction instruments are a starting point, but synchrotron diffraction offers better intensity and signal-to-noise for studying new materials," Khoury said in an email. "Pair Distribution Function (PDF) analysis bridges gaps between crystalline and amorphous materials, it's helping us discover properties we couldn't study before."
Future directions in material science
The future of material science lies in bridging the gap between the unknown and the understood, especially in complex systems.
"There's a tremendous amount of unknown," Liu said. "With artificial intelligence, we have a huge opportunity to crack open these challenges."
Advanced computational tools are poised to accelerate this process, offering unprecedented precision and predictive power.
The integration of tools like X-ray imaging has already proven invaluable in fields like energy storage.
"We used a lot of X-ray imaging for understanding the batteries," Rajh said, "you could monitor how the oxidation state changes as you put lithium in, lithium out."
Such detailed observations allow researchers to fine-tune materials for enhanced performance.
Liu emphasized that achieving breakthroughs requires cutting-edge tools.
"You need atomic resolution, ultra-fast techniques ... to analyze the behavior of single atoms,” Liu said.
These techniques are unlocking the secrets of matter, rediscovering mysteries long hidden, and shedding light on structures that have eluded understanding for generations. They reveal the unseen rhythms of the material world, paving the way for innovation and discovery.
Edited by Sophia Ramirez, Sophia Braccio and Natalia Jarrett.
Reach the reporter at dmanatou@asu.edu.
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Dimitra is a junior studying biomedical engineering and physics. This is her second semester with The State Press. She has also worked as a research assistant in Kirian Lab.
