Promising new alloy for resistive switching memory

Tiny nanoscale filaments could be breakthrough for smaller, denser memory devices

2013-09-20

(Press-News.org) WASHINGTON, D.C. Sept. 20, 2013 -- Memory based on electrically-induced "resistive switching" effects have generated a great deal of interest among engineers searching for faster and smaller devices because resistive switching would allow for a higher memory density.

Researchers have tested a number of oxide materials for their promise in resistive switching memories, and now a team of researchers in Singapore have demonstrated how conductive nano-filaments in amorphous titanium dioxide (TiO2) thin films could be utilized for resistive switching device applications.

Yuanmin Du, Andrew Thye Shen Wee and researchers from the National University of Singapore and the Agency for Science, Technology and Research (A*STAR) of Singapore, describe their results in the journal AIP Advances, which is produced by AIP Publishing.

How Resistive Switching Works

The basic idea of a resistive switching device is that an oxide, which normally acts as an insulator, can be transformed into a conductor, creating a nanoscale filament by using a sufficiently high voltage. With a RRAM (Resistive Random-Access Memory) device comprising of a single filament, two distinct resistance states ("1" and "0") can be obtained through a simple process of filament rupture and re-formation.

The conductivity of the oxide thin films can be adjusted by changing the deposition conditions. "During the measurements of the as-deposited amorphous TiO2 based resistive switching devices, it was found that the oxide thin films initially have good conductivity. This implies that a high electrical breakdown initialization process is not required, as reported in many other switching devices using highly insulating oxide thin films," says Du. "The Conductive Atomic Force Microscopy (CAFM) experiments further confirmed that it is possible to form conductive filaments in oxide thin films through a localized transition by an electrical field."

This research team applied both CAFM and KPFM (Kelvin Probe Force Microscopy), a unique approach that allowed the explanation of the observed resistive switching phenomena. Instead of treating filamentary and interfacial effects separately as done previously, both effects were integrated into one filament-interface model, which could help guide the design of RRAM based devices.

The evidence of high density and uniformly distributed nano-filaments implies that high-density memory cells could be made using such oxide thin films. Such materials are promising for future applications. The small dimension of the formed filament provides great advantages over current technology, as Du explains. "In addition to TiO2, we believe that many other oxides could also have the similar properties."

INFORMATION:

The article "The resistive switching in TiO2 films studied by conductive atomic force microscopy and Kelvin probe force microscopy" by Yuanmin Du, Amit Kumar, Hui Pan, Kaiyang Zeng, Shijie Wang, Ping Yang and Andrew Thye Shen Wee appears in the journal AIP Advances. See: http://dx.doi.org/10.1063/1.4818119

ABOUT THE JOURNAL

AIP Advances is a fully open access, online-only, peer-reviewed journal. It covers all areas of applied physical sciences. With its advanced web 2.0 functionality, the journal puts relevant content and discussion tools in the hands of the community to shape the direction of the physical sciences. See: http://aipadvances.aip.org

ELSE PRESS RELEASES FROM THIS DATE:

Densest array of carbon nanotubes grown to date

2013-09-20

WASHINGTON, D.C. Sept. 20, 2013 -- Carbon nanotubes' outstanding mechanical, electrical and thermal properties make them an alluring material to electronics manufacturers. However, until recently scientists believed that growing the high density of tiny graphene cylinders needed for many microelectronics applications would be difficult. Now a team from Cambridge University in England has devised a simple technique to increase the density of nanotube forests grown on conductive supports about five times over previous methods. The high density nanotubes might one day replace ...

Microfluidic platform gives a clear look at a crucial step in cancer metastasis

2013-09-20

CAMBRIDGE, Mass-- Cancer cells metastasize in several stages -- first by invading surrounding tissue, then by infiltrating and spreading via the circulatory system. Some circulating cells work their way out of the vascular network, eventually forming a secondary tumor. While the initial process by which cancer cells enter the bloodstream -- called intravasation -- is well characterized, how cells escape blood vessels to permeate other tissues and organs is less clear. This process, called extravasation, is a crucial step in cancer metastasis. Now researchers at MIT ...

Personality a key factor in health care use

2013-09-20

Psychiatrists and psychologists have long understood that an individual's personality can define how he or she views the world around them, reacts to situations, and interacts with others. It now appears that personality traits can be linked to the frequency with which older adults use expensive health care services. A study, published today in the journal The Milbank Quarterly, finds that certain measurable personality characteristics can be correlated to health care consumption, in some instances increasing use high cost health care services such as emergency room ...

3 new species of tiny frogs from the remarkable region of Papua New Guinea

2013-09-20

Three new species of tiny frogs from Papua New Guinea are described in the latest issue of Zookeys. Dr Fred Kraus, University of Michigan, who in 2011 in Zookeys described the world's smallest frogs Paedophryne dekot and Paedophryne verrucosa, now adds another 3 species from the genus Oreophryne to the remarkable diversity of this region. The three new species Oreophryne cameroni, Oreophryne parkopanorum and Oreophryne gagneorum are all rather minute, with total body lengths of around 20 mm. These tiny frogs, however are still substantially larger than the species that ...

NASA sees super-rapid intensification of Supertyphoon Usagi

2013-09-20

The radar on the Tropical Rainfall Measuring Mission (TRMM) satellite captured an image of Supertyphoon Usagi near the end of a 24-hour period in which Usagi intensified by 65 knots. This is more than twice the commonly used 30-knot threshold for defining rapid intensification. The TRMM data was used to create a 3-D image. The data was collected at 1035 UTC/6:35 a.m. EDT on Thursday, September 19, 2013, when Usagi was at category 3 on the Saffir-Simpson hurricane intensity scale. A few hours later, Usagi completed its lightning-fast intensification to category 5, the ...

NSF report details increase in business research and development

2013-09-20

According to a recent study published by the National Science Foundation (NSF), businesses spent more on research and development (R&D) in 2011 than they did in 2010. Companies spent $294 billion on R&D performed in the United States during 2011, compared with $279 billion during 2010. Data are from the Business and R&D and Innovation Survey (BRDIS), which is co-sponsored by NSF and the U.S. Census Bureau. BRDIS revealed that during 2011, companies in manufacturing industries performed $201 billion, or 68 percent, of domestic R&D. Companies in nonmanufacturing industries ...

Lithosphere interprets earth

2013-09-20

Boulder, Colo., USA -- The October 2013 Lithosphere is now online. Locations studied include the Central Iberian Massif in Spain; Arctic Alaska; the Wet Mountains of Central Colorado, USA; the Basgo Formation in northwest India; Crystal Geyser in southeastern Utah, USA; Knight Inlet in the southwestern Coast Mountains Batholith, British Columbia, Canada; and three crustal-scale shear zones in the western Canadian Shield of northern Saskatchewan. Lithosphere is published bimonthly in hardcopy; articles are posted online as they become available. Abstracts are online at ...

Researchers identify a switch that controls growth of most aggressive brain tumor cells

2013-09-20

DALLAS -- Researchers at UT Southwestern Medical Center have identified a cellular switch that potentially can be turned off and on to slow down, and eventually inhibit the growth of the most commonly diagnosed and aggressive malignant brain tumor. Findings of their investigation show that the protein RIP1 acts as a mediator of brain tumor cell survival, either protecting or destroying cells. Researchers believe that the protein, found in most glioblastomas, can be targeted to develop a drug treatment for these highly malignant brain tumors. The study was published online ...

Geoscience Workforce Currents #75 and #76

2013-09-20

Alexandria, VA - The American Geosciences Institute (AGI) has released two final reports on the results of an April 2012 workshop for a cohort made up of underrepresented minority individuals seeking careers in academia. The workshop was hosted by AGI and the National Academy of Engineering (NAE) to disseminate information about opportunities available to future geoscience faculty from member societies, the federal government and by developing campus leadership. Over a 13-month period participants were polled on questions related to how they engaged these entities and what ...

Pioneering black carbon researcher receives UN 'Champion of the Earth' award

2013-09-20

Veerabhadran Ramanathan, a distinguished professor of climate and atmospheric sciences at Scripps Institution of Oceanography, UC San Diego, whose landmark research showed that cutting emissions of black carbon and other short lived climate pollutants can significantly lessen the impacts of regional and global climate change, improve the health of millions of rural poor, and avoid crop losses, will receive tonight a 2013 Champions of the Earth award, the United Nations's highest environmental accolade. The Champions of the Earth prize is awarded annually to leaders from ...

NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research

Promising new alloy for resistive switching memory

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: