Structural consequences of nanolithography

August 11, 2011
Ferroelectric domains written by PFM exhibit a subtle structural distortion that can be directly observed using hard X-ray nanodiffraction microscopy.

(PhysOrg.com) -- Users from the University of Wisconsin-Madison and the Center for Nanophase Materials Science, working with the X-Ray Microscopy Group, have discovered structural effects accompanying the nanoscale lithography of ferroelectric polarization domains. The results shed new light on the physics of structural changes induced during this model nanoscale lithographic process.

Developing the means to manipulate nanoscale patterns at their fundamental length scales has led to tremendous growth in the applications of scanning probe lithography. The potential of these capabilities has not yet been fully realized, in part because the large number of sometimes subtle physical processes involved have not yet been sufficiently well described. X-ray nanodiffraction microscopy performed at the Hard X-Ray was used to probe a pattern written into a ferroelectric layer by using scanning-probe ferroelectric nanolithography. This adaptation of piezoresponse force microscopy (PFM) can be used to write arbitrary nanoscale domain patterns into a ferroelectric thin film. The stable strain pattern observed shows the overall shape of the film is unchanged, but the is modified.

Modeling shows that the writing process induces a structural electromechanical response to unscreened charges at surfaces and interfaces, altering the local free energy of written ferroelectric domains.

The ferroelectric lithography approach is one of a number of emerging ways to control nanoscale with scanning probes, which in other systems also can provide control of magnetic and charge-ordered domains. The researchers found that a crystallographic distortion in the lattice of the ferroelectric Pb(Zr,Ti)O3 (PZT) thin film arises from the nanoscale electromechanical response to unscreened charges at surfaces and interfaces. The resulting increase in the free energy of written domains inferred from this poses an important limit for ferroelectric nanolithography. Based on this insight, it will be possible to extend the capability of PFM and other nanoscale patterning methods using direct local structural information.

Explore further: Shocking: Environmental chemistry affects ferroelectric film polarity the same way electric voltage does

More information: J. Y. Jo et al., “Structural Consequences of Ferroelectric Nanolithography,” Nano Lett., Article ASAP (Web 10.1021/nl2009873) (2011).

Related Stories

Reverse Chemical Switching of a Ferroelectric Film

February 25, 2009

(PhysOrg.com) -- Ferroelectric materials display a spontaneous electric polarization below the Curie temperature that can be reoriented, typically by applying an electric field. In this study, researchers from Argonne, Northern ...

Highlight: Nanoscale piezoresponse of ferroelectric domains

October 20, 2009

The first fundamental studies of the dependence of ferroelectric domain configuration and switching behavior on the shape of epitaxial BiFeO3 (BFO) nanostructures has been reported by users from Northwestern University, Korea ...

Measuring the electrical properties of nano-crystals

October 20, 2010

The UK's National Physical Laboratory (NPL) is working to provide more reliable measurement of the electrical properties of materials used in nanotechnology – which could lead to much more accurate devices in the future.

Small and stable ferroelectric domains

March 28, 2011

Researchers are one step closer to figuring out a way to make nano-sized ferroelectric domains more stable, reports a new study in journal Science.

Recommended for you

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Could stronger, tougher paper replace metal?

July 24, 2015

Researchers at the University of Maryland recently discovered that paper made of cellulose fibers is tougher and stronger the smaller the fibers get. For a long time, engineers have sought a material that is both strong (resistant ...

0 comments

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.