PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Physicists pinpoint key property of material that both conducts and insulates

2013-08-22
(Press-News.org) It is well known to scientists that the three common phases of water – ice, liquid and vapor – can exist stably together only at a particular temperature and pressure, called the triple point.

Also well known is that the solid form of many materials can have numerous phases, but it is difficult to pinpoint the temperature and pressure for the points at which three solid phases can coexist stably.

Scientists now have made the first-ever accurate determination of a solid-state triple point in a substance called vanadium dioxide, which is known for switching rapidly – in as little as one 10-trillionth of a second – from an electrical insulator to a conductor, and thus could be useful in various technologies.

"These solid-state triple points are fiendishly difficult to study, essentially because the different shapes of the solid phases makes it hard for them to match up happily at their interfaces," said David Cobden, a University of Washington physics professor.

"There are, in theory, many triple points hidden inside a solid, but they are very rarely probed."

Cobden is the lead author of a paper describing the work, published Aug. 22 in Nature.

In 1959, researchers at Bell Laboratories discovered vanadium dioxide's ability to rearrange electrons and shift from an insulator to a conductor, called a metal-insulator transition. Twenty years later it was discovered that there are two slightly different insulating phases.

The new research shows that those two insulating phases and the conducting phase in solid vanadium dioxide can coexist stably at 65 degrees Celsius, give or take a tenth of a degree (65 degrees C is equal to 149 degrees Fahrenheit).

To find that triple point, Cobden's team stretched vanadium dioxide nanowires under a microscope. The team had to build an apparatus to stretch the tiny wires without breaking them, and it was the stretching that allowed the observation of the triple point, Cobden said.

It turned out that when the material manifested its triple point, no force was being applied – the wires were not being stretched or compressed.

The researchers originally set out simply to learn more about the phase transition and only gradually realized that the triple point was key to it, Cobden said. That process took several years, and then it took a couple more to design an experiment to pin down the triple point.

"No previous experiment was able to investigate the properties around the triple point," he said.

He regards the work as "just a step, but a significant step" in understanding the metal-insulator transition in vanadium dioxide. That could lead to development of new types of electrical and optical switches, Cobden said, and similar experiments could lead to breakthroughs with other materials.

"If you don't know the triple point, you don't know the basic facts about this phase transition," he said. "You will never be able to make use of the transition unless you understand it better."



INFORMATION:



Co-authors are UW physics graduate students Jae Hyung Park, T. Serkan Kasirga and Zaiyao Fei; undergraduates Jim Coy and Scott Hunter; and postdoctoral researcher Chunming Huang. The work was funded by the U.S. Department of Energy.

For more information, contact Cobden at 206-543-2686 or cobden@uw.edu.



ELSE PRESS RELEASES FROM THIS DATE:

Insecticide-treated bed nets critical to global elimination of filariasis

2013-08-22
An international team of scientists have demonstrated that a simple, low-cost intervention holds the potential to eradicate a debilitating tropical disease that threatens nearly 1.4 billion people in more than six dozen countries. The researchers, including Case Western Reserve University School of Medicine professor James Kazura, MD, found that insecticide-treated bed nets reduce transmission of lymphatic filariasis to undetectable levels – even in the absence of additional medication. Their study appears in the August 22 issue of The New England Journal of Medicine. The ...

Studies show vedolizumab is an effective treatment for Crohn's disease and ulcerative colitis

2013-08-22
VIDEO: An international clinical trial led by Dr. Brian Feagan of Western University in London, Canada has found that the investigational antibody vedolizumab is an effective treatment for those suffering from... Click here for more information. An international clinical trial led by Dr. Brian Feagan of Western University in London, Canada, has found that the investigational antibody vedolizumab is an effective treatment for those suffering from ulcerative colitis (UC) and ...

Family history of diabetes increases the risk of prediabetes by 26 percent, with effect most evident in non-obese

2013-08-22
A study involving more than 8,000 participants has shown that people with a family history of diabetes see their risk of prediabetes increase by 26%. The research is published in Diabetologia, the journal of the European Association for the Study of Diabetes, and is by Dr Andreas Fritsche and colleagues from the German Center for Diabetes Research*. Prediabetes is a condition most often described as the 'state between normal blood sugar control and full diabetes', and indeed prediabetes progresses to full blown diabetes in up to 20% of individuals affected per year. ...

Breast is best: Good bacteria arrive from mum's gut via breast milk

2013-08-22
Scientists have discovered that important 'good' bacteria arrive in babies' digestive systems from their mother's gut via breast milk. Although this does confirm that when it comes to early establishment of gut and immune health, 'breast is best', a greater understanding of how babies acquire a population of good bacteria can also help to develop formula milk that more closely mimics nature. The study, published today (22 August) in Environmental Microbiology, which is a journal of the Society for Applied Microbiology (SfAM), was led by Professor Christophe Lacroix ...

New health economics study highlights societal benefits of knee replacement surgery

2013-08-22
Rosemont, Ill. – The full impact of knee replacement surgery on both patients' lives and on society includes significant overall cost savings, according to a new study published in the Journal of Bone and Joint Surgery (JBJS). Researchers found that for the average patient undergoing knee replacement surgery, the expense of surgery is offset by indirect savings of nearly $40,000. This translates to an average lifetime societal benefit of $10,000-$30,000. Most of the societal savings come from the patient's ability to maintain employment and increase earnings over a longer ...

Pazopanib shows better quality-of-life in advanced kidney cancer

2013-08-22
BOSTON -- Two oral targeted drugs approved for metastatic kidney cancer worked equally well, but one proved superior in tolerability, according to results of a large international clinical trial led by researchers at Dana-Farber Cancer Institute. Pazopanib (Votrient) and sunitinib (Sutent), both recently approved as first-line treatments for advanced renal cell cancer, had similar benefits in delaying progression of the disease, but the safety profile and many measures of quality of life favored pazopanib, suggesting a potential shift in standard of care in metastatic ...

Study finds mother's genes can impact aging process

2013-08-22
As we age, our cells change and become damaged. Now, researchers at Karolinska Institutet and the Max Planck Institute for Biology of Aging have shown that aging is determined not only by the accumulation of changes during our lifetime but also by the genes we acquire from our mothers. The results of the study are published in the journal Nature. There are many causes of aging that are determined by an accumulation of various kinds of changes that impair the function of bodily organs. Of particular importance in aging, however, seems to be the changes that occur in the ...

A brighter method for measuring the surface gravity of distant stars

2013-08-22
Astronomers have found a clever new way to slice and dice the flickering light from a distant star in a way that reveals the strength of gravity at its surface. That is important because a star's surface gravity is one of the key properties that astronomers use to calculate a star's physical properties and assess its evolutionary state. The new technique can also be used to significantly improve estimates of the sizes of the hundreds of exoplanets that have been discovered in the last 20 years. Current estimates have uncertainties ranging from 50 percent to 200 percent. ...

New results from Daya Bay

2013-08-22
The international Daya Bay Collaboration has announced new results about the transformations of neutrinos - elusive, ghostlike particles that carry invaluable clues about the makeup of the early universe. The latest findings include the collaboration's first data on how neutrino oscillation – in which neutrinos mix and change into other "flavors," or types, as they travel – varies with neutrino energy, allowing the measurement of a key difference in neutrino masses known as "mass splitting." "Understanding the subtle details of neutrino oscillations and other properties ...

Berlin researchers open a door for solid state physics

2013-08-22
Without the currently available plethora of X-ray methods, basic research in the physical sciences would be unthinkable. The methods are used in solid state physics, in the analysis of biological structures, and even art historians have X-rays to thank for many new insights. Now, scientists at the Helmholtz Center Berlin (HZB) have identified yet another area of application. The team around Dr. Martin Beye and Prof. Alexander Föhlisch was able to show that solids lend themselves to X-ray analysis based on nonlinear physical effects. Until now, this could only be done using ...

LAST 30 PRESS RELEASES:

Cesarean delivery linked to higher risk of pain and sleep problems after childbirth

New global burden of disease study: Mortality declines, youth deaths rise, widening health inequities

Chemobiological platform enables renewable conversion of sugars into core aromatic hydrocarbons of petroleum

Individualized perioperative blood pressure management in patients undergoing major abdominal surgery

Proactive vs reactive treatment of hypotension during surgery

Different types of depression linked to different cardiometabolic diseases

Ketogenic diet may protect against stress experienced in the womb

Adults 65 years and older not immune to the opioid epidemic, new study finds

Artificial intelligence emerging as powerful patient safety tool in pediatric anesthesia

Mother’s ZIP code, lack of access to prenatal care can negatively impact baby’s health at birth, new studies show

American Society of Anesthesiologists honors John M. Zerwas, M.D., FASA, with Distinguished Service Award

A centimeter-scale quadruped piezoelectric robot with high integration and strong robustness

Study confirms that people with ADHD can be more creative. The reason may be that they let their mind wander

Research gives insight into effect of neurodegenerative diseases on speech rhythm

Biochar and plants join forces to clean up polluted soils and boost ecosystem recovery

Salk scientist Joseph Ecker awarded McClintock Prize for Plant Genetics and Genome Studies

ADHD: Women are diagnosed five years later than men, despite symptoms appearing at the same age.

Power plants may emit more pollution during government shutdowns

Increasing pressures for conformity de-skilling and demotivating teachers, study warns

Researchers develop smarter menstrual product with potential for wearable health monitoring

Microwaves for energy-efficient chemical reactions

MXene current collectors could reduce size, improve recyclability of Li-ion batteries

Living near toxic sites linked to aggressive breast cancer

New discovery could open door to male birth control

Wirth elected Fellow of American Physical Society

The Journal of Nuclear Medicine Ahead-of-Print Tip Sheet: October 10, 2025

Destined to melt

Attitudes, not income, drive energy savings at home

The playbook for perfect polaritons

‘Disease in a dish’ study of progressive MS finds critical role for unusual type of brain cell

[Press-News.org] Physicists pinpoint key property of material that both conducts and insulates