Discovery of Current Spike Phenomenon in Semiconductor Materials Leads to New Understanding of Nanoscale Plasticity

Mar 31, 2009

Plasticity in certain semiconductor materials at the nanoscale is actually linked to phase transformation rather than dislocation nucleation, as previously thought. This is shown by the results of an international research team led by Professor Roman Nowak of the Nordic Hysitron Laboratory (NHL) at Helsinki University of Technology, just published in the Nature Nanotechnology journal in an article entitled “An electric current spike linked to nanoscale plasticity”.

Plasticity has always been associated with defect movement or initiation, but Nowak’s team has proved that plasticity can indeed start from non-dislocation processes, and that this phase transformation occurs in a stressed nano-volume, changing from one to another without affecting defect activity. The phenomenon, named the “Current Spike”, is clearly visible, and its explanation relies heavily on advanced physics.

“The implications of these findings are such that our understanding of material behavior in the nano-regime may just need to be revised once again. If this approach is further developed to encompass other sets of materials than the ones studied here, this new evidence will certainly lead to many advances in pressure-sensing and pressure-switching applications, just to name one of many potential benefactors of these newly-revealed discoveries,” Nowak says.

While certainly enlightening on their own, the NHL’s recently-published findings represent the first critical steps towards addressing an intriguing larger issue: Under which conditions and at which length scales does combined mechanical-electrical coupling lead to similar effects? NHL will be leading the way and acting as a source of inspiration in this quest for understanding of the deformation of materials at .

The main target of NHL is the mechanical characterization of and nanostructures using the nanoindentation testing technique. An instrument developed by Hysitron, Inc. of Minneapolis, USA allows for a quantitative and concurrent measurement of the mechanical and electrical properties. These experiments are complemented by computational methods, with the aim of exploring nanometer-size contacts in the material and arrive at the final unique clarification.

The NHL’s success stems from well-targeted and carefully-organised collaboration with the best experts in the field. Both the NHL’s efficiency and effectiveness are demonstrated by the recent publication, which was only made possible by virtue of the synergistic combination of the expertise in atomistic calculations of Professor Nowak and two visiting researchers, together with sophisticated nano-experimentation by Hysitron, Inc, USA, and a top proficiency in the production of advanced semiconductors at the Tampere University of Technology.

More information: “An electric current spike linked to nanoscale plasticity”, R. Nowak, D. Chrobak, and S.Nagao, NHL, D. Vodnick and M. Berg, Hysitron Inc., A. Tukiainen and M. Pessa, Tampere University of Technology. Nature Nanotechnology. on-line version: 22 March 2009 | doi:10.1038/nnano.2009.49,… s/nnano.2009.49.html

Provided by Academy of Finland

Explore further: 3-D images of tiny objects down to 25 nanometres

Related Stories

Hey fever! The surprise benefit of allergies

Jul 29, 2008

Long-suffering victims of allergies such as asthma and hay fever might enjoy a surprise benefit, according to research led by the University of New South Wales (UNSW).

A new window into the deformation of nanoscale materials

Aug 13, 2006

Materials on the nanoscale don't always have the same properties they would in bulk; for one thing, nanomaterials are often a lot harder. Unlike most bulk materials, a crystal that is small enough can be perfect, ...

Drinking alcohol may lower risk of non-Hodgkin's lymphoma

Aug 15, 2005

People who drink alcohol have a lower risk of non-Hodgkin's lymphoma (NHL) than non-drinkers, researchers at Yale's Department of Epidemiology and Public Health (EPH) write in an article published in Lancet Oncology.

Tension in the nanoworld

Jan 23, 2009

( -- A joint team of researchers at CIC nanoGUNE (San Sebastian, Spain) and the Max Planck Institutes of Biochemistry and Plasma Physics (Munich, Germany) report the non-invasive and nanoscale ...

Recommended for you

3-D images of tiny objects down to 25 nanometres

Mar 30, 2015

Scientists at the Paul Scherrer Institute and ETH Zurich (Switzerland) have created 3D images of tiny objects showing details down to 25 nanometres. In addition to the shape, the scientists determined how ...

Solving molybdenum disulfide's 'thin' problem

Mar 27, 2015

The promising new material molybdenum disulfide (MoS2) has an inherent issue that's steeped in irony. The material's greatest asset—its monolayer thickness—is also its biggest challenge.

Snowflakes become square with a little help from graphene

Mar 25, 2015

The breakthrough findings, reported in the journal Nature, allow better understanding of the counterintuitive behaviour of water at the molecular scale and are important for development of more efficient techno ...

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.