Study: nanostructures hold promise as fast, tiny RRAM switches

Jan 15, 2010
Jay A. Switzer's research may lead to advances in computing and resistive random access memory (RRAM)

(PhysOrg.com) -- Building microscopic materials known as superlattices on the surface of gold may lead to a treasure for researchers interested in faster, smaller, and more energy efficient computing devices, say researchers at Missouri University of Science and Technology.

Dr. Jay A. Switzer and his colleagues at Missouri S&T report in the Journal of the American Chemical Society that they have constructed a type of superlattice that shows "unique low-to-high and high-to-low resistance switching that may be applicable to the fabrication of an emerging memory device known as resistive random access memory," or RRAM.

With RRAM, a material that is normally insulating can be made to conduct through a filament or conduction path formed after a high enough voltage is applied.

The researchers' paper, titled Resistance Switching in Electrodeposited Magnetite Superlattices, appears on the journal's ASAP ("as soon as publishable") website and will appear in an upcoming issue.

Superlattices are nanometer-scale structures made up of two materials layered on top of each other, like the alternating bread and meat in a club sandwich. A nanometer - visible only with the aid of a high-power electron microscope - is one billionth of a meter, and some nanomaterials are only a few atoms in size. By experimenting with materials at the nanometer level, researchers find that even common materials exhibit unusual properties. For example, metals developed at the nanometer scale may have fewer defects and could lead to stronger materials for construction. Semiconductors and magnetic materials developed at the nanometer scale may have different properties than the bulk material.

At Missouri S&T, Switzer and his colleagues produced two types of superlattices - known as defect-chemistry and compositional superlattices - from the materials magnetite and zinc ferrite. They then "grew" the materials on the single-crystal gold placed in a beaker filled with a solution.

The superlattices grown via the defect-chemistry method appear to hold promise for RRAM devices, Switzer says, because the resistance of the superlattice is a function of the applied bias. The fact that multiple resistance states can be accessed by simply varying the applied voltage opens up new possibilities for multi-bit data storage and retrieval.

Switzer's co-authors for the paper are Rakesh V. Gudavarthy, Guojun Mu, and Zhen He, all graduate students in the chemistry department at Missouri S&T; Andrew J. Wessel, an undergraduate student in the chemistry department at Missouri S&T; and Dr. Elizabeth A. Kulp, a postdoctoral associate at Missouri S&T.

Last fall, Switzer and his colleagues reported in Chemistry of Materials that a simple, inexpensive process of growing zinc oxide "nanospears" could also lead to new materials for solar cells, ultraviolet lasers, solid-state lighting and piezoelectric devices (see Tilted Epitaxial ZnO Nanospears on Si(001) by Chemical Bath Deposition).

Explore further: The latest fashion: Graphene edges can be tailor-made

More information: pubs.acs.org/doi/abs/10.1021/ja909295y

Related Stories

Red-hot research could lead to new materials

Apr 09, 2009

(PhysOrg.com) -- Recent experiments to create a fast-reacting explosive by concocting it at the nanoscopic level could result in more spectacular firework displays. But more impressive to the Missouri University ...

Creating exotic oxide-based spintronic devices

Apr 03, 2006

Physicist Jak Tchakhalian studies what occurs in the interface of two incompatible nanomaterials made of complex oxides that are produced by laser pulses. In the process, what emerges is an extremely exotic ...

Silicon superlattices: New waves in thermoelectricity

Apr 01, 2009

(PhysOrg.com) -- A University of Wisconsin-Madison research team has developed a new method for using nanoscale silicon that could improve devices that convert thermal energy into electrical energy.

Recommended for you

The latest fashion: Graphene edges can be tailor-made

Jan 23, 2015

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Nanotechnology changes behavior of materials

Jan 23, 2015

One of the reasons solar cells are not used more widely is cost—the materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices ...

Gold 'nano-drills'

Jan 22, 2015

Spherical gold particles are able to 'drill' a nano-diameter tunnel in ceramic material when heated. This is an easy and attractive way to equip chips with nanopores for DNA analysis, for example. Nanotechnologists ...

The importance of building small things

Jan 22, 2015

Strong materials, such as concrete, are usually heavy, and lightweight materials, such as rubber (for latex gloves) and paper, are usually weak and susceptible to tearing and damage. Julia R. Greer, professor ...

Graphene brings quantum effects to electronic circuits

Jan 22, 2015

Research by scientists attached to the EC's Graphene Flagship has revealed a superfluid phase in ultra-low temperature 2D materials, creating the potential for electronic devices which dissipate very little ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.