Posts showcasing the wonder, beauty, and potential of cutting-edge materials research—freely contributed by physicists from across the country. (Funsize Physics is not responsible for any minds that are blown.)
You may know that the media used in magnetic recording technologies, such as computer hard drives, are made of millions of tiny nanomagnets. Each nanomagnet can be switched up or down to record bits of information as ones and zeros. These media are constantly subjected to magnetic fields in order to write, read, and erase information. If you have ever placed a magnet too close to your laptop or cell phone, you know that exposure to an external magnetic field can disrupt information stored this way. Did you know that it is possible for the nanomagnets to "remember" their previous state, if carefully manipulated under specific magnetic field and temperature conditions? Using a kind of memory called topological magnetic memory, scientists have found out how to imprint memory into magnetic thin films by cooling the material under the right conditions.
Solids are generally divided into metals, which conduct electricity, and insulators, which do not. Some oxides straddle this boundary, however: a material's structure and properties suggest it should be a metal, but it sometimes behaves as an insulator. Researchers at the University of California, Santa Barbara are digging into the mechanisms of this transformation and are aiming to harness it for use in novel electronic devices.
Diodes, also known as rectifiers, are a basic component of modern electronics. As we work to create smaller, more powerful and more energy-efficient electronic devices, reducing the size of diodes is a major objective. Recently, a research team from the University of Georgia developed the world's smallest diode using a single DNA molecule. This diode is so small that it cannot be seen by conventional microscopes.
Most electronics are made out of rigid materials like silicon, but it is possible to make wires and other electronics using entirely soft and squishy materials. By utilizing liquid metal nanoparticles, we can even draw wires by hand using light pressure from a magic marker to squish the particles together.
Essentially all of our technology is built by manipulating materials on length scales between a tenth of a billionth of a meter (atom-sized) and a thousand meters (skyscraper-sized). We call this range of sizes "funsize."
Materials that are absolutely perfect—in other words, materials that contain no defect of any kind—are usually not very interesting. Imagine being married to a saint: you would quickly be bored out of your mind! Defects and impurities can considerably change many properties of materials in ways that allow a wide range of applications.
It's a solid . . . it's a liquid . . . it's a LIQUID CRYSTAL! Researchers at the University of Wisconsin-Madison Materials Research Science and Engineering Center are investigating how the unique properties of liquid crystals allow them to act as environmental sensors, detecting toxins in the environment. In this video, we give a brief overview of what liquid crystals are and how their properties can be utilized to improve the world.
Many solid materials have a crystal structure, with atoms that exist in a particular, organized arrangement. The degree of organization can vary among crystals, however. High-quality crystalline materials are the foundation of many familiar devices, such as integrated circuits and solar cells. A better understanding of these materials and how to produce them is important for developing new technologies.
Scientists are working to develop electronic devices that store and process information by manipulating a property of electrons called spin—a research area aptly known as spintronics. The semiconductors we are developing will not only be faster and cheaper than those used in conventional devices, but will also have more functionality.
Carbon-based nanostructures are among the most intensely studied systems in nanotechnology. Potential practical applications span the fields of medicine, consumer electronics, and hydrogen storage, and they could even be used to develop a space elevator. A research team at the University of Northern Iowa is probing the properties of multilayered carbon nanostructures known as "carbon onions."
Scientists and engineers are making smaller and smaller structures designed to control the quantum states of electrons in a material. By controlling quantum mechanics, we can create new materials that do not exist in nature, develop more efficient solar cells and faster computer chips, and even discover exotic new states of matter.
There are many ways atoms can arrange microscopically to form crystalline materials. Interestingly, materials created from different arrangements of the same atoms may exhibit completely different physical and chemical properties. A method called thin film epitaxy allows scientists not only to fine-tune the properties of known materials, but also to generate completely new materials with structures and properties not found in nature.
Superconductors and magnetic fields do not usually get along, but a research team led by a Brown University physicist has produced new evidence for an exotic superconducting state that can indeed arise when a superconductor is subject to a strong magnetic field. Their results could enable scientists to develop materials for more efficient memory storage, and even help to explain the behavior of distant astronomical objects called pulsars.
A bit of stray moisture during an experiment tipped off scientists about the strange behavior of a complex oxide material they were studying—shedding light on its potential for improving chemical sensors, computing and information storage. In the presence of a water molecule on its surface, the layered material emits ultraviolet light from its interior.
Transparent conducting oxides are unusual but highly useful materials that combine transparency to visible light, similar to glass, with high electrical conductivity, similar to copper and other metals.