Sentences with word «hafnium»

«Since the structures of this material are compatible with silicon technology, we can expect that new non-volatile memory devices with ferroelectric polycrystalline layers of hafnium oxide will be able to be built directly onto silicon in the near future,» says the corresponding author of the study and head of the Laboratory of Functional Materials and Devices for Nanoelectronics, Andrei Zenkevich.

Instead of probing a beam of neutral particles, they confine molecular ions of hafnium fluoride in a rotating electric field, which causes the ions to trace out little circles rather than flying away.

Hafnium bombs: In an episode reminiscent of the Cold Fusion debacle, DARPA forked out $ 7 million in the 1990s for research into a bomb predicted to release huge gamma - ray bursts without creating any nuclear fallout.

«Scientists grow a material based on hafnium oxide for a new type of non-volatile memory.»

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to determine the ferroelectric properties of an inorganic compound called hafnium oxide (HfO2) for the first time.

Using computer simulations, Brown University engineers predict that a material made with hafnium, nitrogen, and carbon will have a higher melting point than any known material.

«By changing the oxygen defect concentration in hafnium oxide we could unambiguously correlate the state of material with the resistive switching behavior of the memory device,» explains Sankaramangalam Ulhas Sharath, PhD student in the group and first author of the publication.

Tungsten contains one isotope of mass 182 that is created when an isotope of the element hafnium undergoes radioactive decay, meaning its elemental composition changes as it gives off radiation.

During their investigations, the research team came to the surprising result that has been published in the journal Geology: 2.7 billion years ago, seawater contained an unusually high abundance of the radioactive isotope Hafnium 176 but a comparably low abundance of the radioactive isotope Neodymium 143, similar to what can be observed in present day seawater.

To address the problem, Braun and his Illinois colleagues coated tungsten emitters in a nanolayer of a ceramic material called hafnium dioxide.

Many researchers had gauged how long Mars took to form using the steady decay of radioactive hafnium - 182 to tungsten - 182, but the answers were all over the place.

The Temagami Banded Iron Formation, which was formed 2.7 billion years ago during the Neoarchean period, can be used as an archive because the isotopic composition of many chemical elements such as Hafnium and Neodymium directly mirrors the composition of Neoarchean seawater.

Eventually, he adds, the group plans to start using thorium fluoride, which is harder to measure than hafnium fluoride, but whose greater stability offers even longer precession times.

Because hafnium has a higher k - value than silicon dioxide, it should be able to do the same or better job at a thickness that prevents leakage.

The theory was that hitting a small amount of a radioactive isomer of the super-expensive metal hafnium with X-rays would release this torrent of energy.

For solid vessels, the highest melting point recorded is for tantalum hafnium carbide, which has a potential melting point of 4263 kelvin.

The top view of the jungle canopy (hafnium thickness of 2.5 nanometers and gold thickness of 20 nanometers).

In a recent paper just published online in the high impact journal Advanced Functional Materials, the researchers investigated why hafnium oxide based devices are so promising for memory applications and how the material can be tuned to perform at the desired level.

«It's a very, very significant event,» says electrical engineer Carlton Osburn of North Carolina State University, member of a research team that studied hafnium and other advanced transistor materials.

To overcome this obstacle, chipmakers had to determine how to replace silicon dioxide with so - called high - k materials like hafnium and zirconium.

While hafnium oxide is already used in the production of modern silicon logic chips, a few years ago ferroelectric properties were discovered in one of its modifications.

Compounds made from hafnium and carbon have some of the highest known melting points.

A few years ago, DARPA, which prides itself on promoting far - out projects, proposed spending $ 30 million on a «hafnium bomb,» a type of nuclear weapon intended to release energy from atomic nuclei without either fission or fusion, using an approach similar to how energy is extracted from electrons in a laser.

Memory based on hafnium oxide is particularly interesting due to its superior properties.

A Cologne working group involving Prof. Carsten Münker and Dr. Elis Hoffmann and their student Sebastian Viehmann (working with Prof. Michael Bau from the Jacobs University Bremen) have managed for the first time to determine the isotope composition of the rare trace elements Hafnium and Neodymium in 2.7 - billion - year - old seawater by using high purity chemical sediments from Temagami Banded Iron Formation (Canada) as an archive.

Dr. Hoffmann: «The isotope Hafnium 176 in contrast to its counterpart Neodymium 143 was transported by means of weathering into the oceans and became part of iron - rich sediments on the sea floor 2,700 million years ago.»

So Cola, NSF Graduate Research Fellow Erik Anderson and Research Engineer Thomas Bougher replaced the calcium with aluminum and tried a variety of oxide materials on the carbon nanotubes before settling on a bilayer material composed of alumina (Al2O3) and hafnium dioxide (HfO2).

But martian meteorites are bits of martian crust, a rock derived from the mantle by melting, which alters the ratio of hafnium to tungsten.

Furthermore, if ferroelectric tunnel junctions based on hafnium oxide are developed, it can be hoped that they will be able to demonstrate memristor properties.

«Hafnium and tungsten are abundant, low - cost materials, and the process used to make these heat - resistant emitters is well established.

From indium touchscreens to hafnium - equipped moonships, the nether regions of the periodic table underpin modern technology — but supplies are getting scarce

Nuclear reactors utilize control rods made from elements such as cadmium, boron or hafnium, all of which are efficient neutron absorbers.

The problem had been that the hafnium - tungsten dating technique depends not only on measuring the relevant isotopes in meteorites long ago blasted off Mars but also on knowing the relative proportion of hafnium and tungsten in the deep martian mantle.

They found it in the ratio of hafnium - 176 to hafnium - 177, which are identical chemically.

To shrink the uncertainty, Dauphas and Pourmand went looking in a variety of non-martian meteorites for a stand - in for the hafnium - tungsten ratio that would not be altered.

Conclusions based on the technique, called the hafnium - tungsten clock, are still controversial.

Their real breakthrough, however, is discovering the use of an intermediate dielectric coating (hafnium) to block the quenching of the free electrons in the metal by the CNTs, allowing the nanotubes to function uninhibited.

The hafnium coating enables the bunching of gold nanotubes that creates a thick canopy full of sensitive spots for detection.

The joint research team, led by LLNL Engineer Tiziana Bond and ETH Scientist Hyung Gyu Park, are using spaghetti - like, gold - hafnium - coated carbon nanotubes (CNT) to amplify the detection capabilities in surface - enhanced Raman spectroscopy (SERS).

Instead, the Stanford team fabricated memory using titanium nitride, hafnium oxide and platinum.

The material used by Funakubo and co-workers, hafnium oxide (HfO2), had previously been predicted to exhibit ferroelectric properties through first principle calculations.

Hafnium - based insulators are now used in the 45 - nanometer generation of chips made by Intel, shown here below a chip from 1993.

A major innovation has been the development of better insulators made of an alloy of the element hafnium, which reduces heat loss and conserves power.

In its transistors, hafnium oxide plays the role of the so - called gate dielectric, an insulating layer that separates the transistor's electrode from its silicon channel for carrying current.

Producing hafnium oxide transistors would require chipmakers to add multiple new steps to the manufacturing process — in part because the electrodes must be fashioned from metal, instead of from a form of silicon, to remain compatible with the hafnium.

«For me, the difference is that the hafnium bomb violated the laws of physics, and we had lots of really smart people who said it violated the laws of physics,» he says.

Intel's demonstration consisted of a hafnium - based microprocessor capable of running three different computer operating systems.

Ma, who says he has worked with both the Intel and IBM research groups but is not privy to either's design, adds that the presence of silicon dioxide would require chipmakers to add nitrogen to the hafnium oxide as well.

Osburn says that a hafnium transistor would still need a thin layer of silicon dioxide at the bottom of the gate insulator to dissipate excess charges that would otherwise accumulate there and interfere with the device.