Ti-V alloys' superconductivity: Inherent, not accidental

All of the Ti-V alloys could display a relatively high superconducting transition temperature

2014-06-23

(Press-News.org) Physicists from India have shed new light on a long-unanswered question related to superconductivity in so-called transition metal binary alloys. The team revealed that the local magnetic fluctuations, or spin fluctuations, an intrinsic property of Titanium-Vanadium (Ti-V) alloys, influence superconductivity in a way that is more widespread than previously thought. They found that it is the competition between these local magnetic fluctuations and the interaction between electrons and collective excitations, referred to as phonons, which determine the superconductivity. Dr. Matin, from the Raja Ramanna Center for Advanced Technology, Indore, India, and colleagues published their findings in a study in EPJ B.

The authors investigated the underlying mechanisms responsible for the variation of superconducting temperature threshold TC in Ti-V alloys, which can be used in thermonuclear reactors. They measured the temperature and magnetic field dependency of several physical characteristics including resistivity, heat capacity and magnetisation. They also used a microscopic theoretical technique—called density functional theory—to study the density of states at each energy level available for electrons to occupy.

Theoretical predictions provided by the Bardeen Cooper Schrieffer (BCS) theory suggest a high TC on the order of 20 Kelvin (K) for these alloys. By comparison, the authors' experimental value of TC was less than 10 K. They attribute the difference to spin fluctuations in these alloys, which, the authors found, are inherent to the Ti-V alloys.

The authors deduced that these spin fluctuations are reflected in the properties of the normal state of electrons. They therefore influence the superconductivity of the alloys in a similar way to that observed in high-temperature oxide and iron-based superconductors; as such, the influence of spin fluctuations on superconductivity is not necessarily confined to certain classes of exotic compounds, as previously thought.

INFORMATION: Reference: M. Matin, L. S. Sharath Chandra, S. K. Pandey, M. K. Chattopadhyay and S. B. Roy (2014), The influence of electron-phonon coupling and spin fluctuations on the superconductivity of the Ti-V alloys, European Physical Journal B, DOI 10.1140/epjb/e2014-50036-2

For more information visit: http://www.epj.org

The full-text article is available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

Remarkable white dwarf star possibly coldest, dimmest ever detected

2014-06-23

A team of astronomers has identified possibly the coldest, faintest white dwarf star ever detected. This ancient stellar remnant is so cool that its carbon has crystallized, forming -- in effect -- an Earth-size diamond in space. "It's a really remarkable object," said David Kaplan, a professor at the University of Wisconsin-Milwaukee. "These things should be out there, but because they are so dim they are very hard to find." Kaplan and his colleagues found this stellar gem using the National Radio Astronomy Observatory's (NRAO) Green Bank Telescope (GBT) and Very ...

African American women more resistant anti-inflammatory effect aspirin than white women

2014-06-23

CHICAGO, IL — African American women respond differently to the anti-inflammatory effect of aspirin than do white American women, new research finds. The results were presented Monday, June 23 at ICE/ENDO 2014, the joint meeting of the International Society of Endocrinology and the Endocrine Society in Chicago. "African American women appear to be more resistant than white American women to the anti-inflammatory benefits of aspirin in reducing cardiovascular disease and its risk factors," said lead study author Nora Alghothani, MD, MPH, endocrinology fellow in the Division ...

Among weight loss methods, surgery and drugs achieve highest patient satisfaction

2014-06-23

CHICAGO, IL — Obese and overweight Americans who have tried losing weight report far greater overall satisfaction with weight loss surgery and prescription weight loss medications than with diet, exercise and other self-modification methods, an Internet survey finds. The results were presented Saturday at the joint meeting of the International Society of Endocrinology and the Endocrine Society: ICE/ENDO 2014 in Chicago. "This finding may mean that diet and exercise alone just don't work for a lot of people," said Z. Jason Wang, PhD, the study's principal investigator ...

Survey reveals consumers' pecan preferences

2014-06-23

LAS CRUCES, NM – High-profile marketing campaigns for nuts such as pistachios and almonds have become familiar to consumers throughout the United States. Shining a spotlight on these products has increased public awareness and boosted sales. For example, domestic per-capita almond consumption has increased five-fold since 1976, thanks in part to savvy marketing efforts. In contrast, the pecan industry been successful in focusing their efforts on expanding pecan export markets, but pecan consumption in the U.S. has remained relatively flat over the past 35 years. A new survey ...

Physical fitness level affects kidney function in type 2 diabetes

2014-06-23

CHICAGO, IL — Adults with Type 2 diabetes who improve their physical fitness lower their chances of getting chronic kidney disease (CKD), and if they already have kidney damage, they can improve their kidney function. These findings come from a new study presented Monday at the joint meeting in Chicago of the International Society of Endocrinology and the Endocrine Society: ICE/ENDO 2014. Health care providers have long known that exercise has a beneficial impact on overall health and wellness in both the general public and people with Type 2 diabetes. This study, though, ...

Light-emitting diode treatments outperform traditional lighting methods

2014-06-23

QUEBEC – In Canada, where outdoor growing seasons are limited, sales from greenhouse fruit and vegetable production operations still surpass $1.1 billion annually. Finding more efficient methods for providing lighting in greenhouse production is a key component to support these high levels of production and increase revenues. "Light irradiance is the limiting factor for increasing production in greenhouses, when all other factors (temperature, nutrient levels, and water availability) are adequately maintained," said the authors of a new study. McGill University researchers ...

Cancer chain in the membrane

2014-06-23

Supercomputer simulations have shown that clusters of a protein linked to cancer warp cell membranes, according to scientists at The University of Texas Health Science Center at Houston (UTHealth) Medical School. This research on these protein clusters, or aggregates as scientists call them, could help guide design of new anticancer drugs. "The aggregate is a large substructure that imposes some kind of curvature on the membrane — that's really the major observation," said Alemayehu Gorfe, assistant professor of Integrative Biology and Pharmacology at the UTHealth Medical ...

Working parents resort to emergency or urgent care visits to get kids back into child care

2014-06-23

Ann Arbor, Mich. — Substantial proportions of parents chose urgent care or emergency department visits when their sick children were excluded from attending child care, according to a new study by University of Michigan researchers. The study, published today in Pediatrics, also found that use of the emergency department or urgent care was significantly higher among parents who are single or divorced, African American, have job concerns or needed a doctor's note for the child to return. Previous studies have shown children in child care are frequently ill with mild ...

Fungal infection control methods for lucky bamboo

2014-06-23

GAINESVILLE, FL – The popularity of ornamental plants imported to the United States from China is accompanied by concerns about the potential to introduce pathogens into the market. Dracaena, a genus consisting of approximately 40 different species, including the widely recognized "lucky bamboo," is among the most frequently imported group of ornamentals to enter the U.S. for domestic sale and eventual export to Canada. The authors of a new research study say it is crucial to be vigilant about potential pests and pathogens on imported cuttings of Dracaena. "Pests and pathogens ...

Cautionary tales: Mustaches, home oxygen therapy, sparks do not mix

2014-06-23

Rochester, Minn. — Facial hair and home oxygen therapy can prove a dangerously combustible combination, a Mayo Clinic report published in the peer-reviewed medical journal Mayo Clinic Proceedings finds. To reach that conclusion, researchers reviewed home oxygen therapy-related burn cases and experimented with a mustachioed mannequin, a facial hair-free mannequin, nasal oxygen tubes and sparks. They found that facial hair raises the risk of home oxygen therapy-related burns, and encourage health care providers to counsel patients about the risk. MULTIMEDIA ALERT: Video ...

Ti-V alloys' superconductivity: Inherent, not accidental

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: