Nanocrystals grow from liquid interface

May 17, 2013 by Tona Kunz, Argonne National Laboratory
Nanocrystals grow from liquid interface
Illustration of the nano-layer at the liquid interface between the salt solution and mercury. Physicists from Kiel University discovered the formation of an ordered crystal of exactly five atomic layers between the two liquids with brilliant X-rays. Credit: Christian-Albrechts-Universität zu Kiel

An international collaboration of scientists has discovered a unique crystalizing behavior at the interface between two immiscible liquids that could aid in sustainable energy development.

Liquid interface behavior cannot be investigated at atomic level by most modern methods. Only brilliant X-rays at world-leading light sources can investigate this type of important chemical processes.

The result is reported on in the April issue of the journal Proceedings of the National Academy of Science in an article titled "In situ x-ray studies of adlayer-induced crystal nucleation at the liquid-liquid interface."

The team used high-energy, high-brilliance X-rays at the LSS (liquid surface spectrometer) at the 9-ID-C beamline of the Advanced Photon Source (APS) at Argonne National Laboratory and the LISA diffractometer (Liquid Interfaces Scattering Apparatus) at the PETRA III light source at the German laboratory DESY. The research is the continuation and expansion of research done at the APS in 2010.

In their latest work, the researchers from the U.S., Israel and Germany wanted to find out, for the first time, what exactly occurs during chemical growth at liquid interfaces. Led by researchers from the Institute of Experimental and Applied Physics of Kiel University, the team observed the formation of an ordered crystal of exactly five between the two liquids, which acts as a foundation for growing even bigger crystals. This work may result in new semiconductor and nano-particle production processes.

They investigated mercury surface in contact with a salt solution containing lead and bromine (or fluorine) ions and obtained an astonishing result: although both liquids were atomically disordered in the bulk, a nanometre thin layer, that is a ten thousandth of the width of a human hair, with crystalline order was formed at their interface.

The atomic order that develops at the interface of otherwise disordered liquids is not only of fundamental interest for science. In fact, in the last few years, a range of chemical processes for producing materials and nano-particles has employed growth at liquid interfaces. For example, two years ago, American scientists at the University of Michigan developed a similar process for manufacturing semiconductor germanium with an extremely energy-efficient method from its oxide.

Further developments of such processes could help to reduce the high energy costs in the production of solar cells. In order to make such advances, a better understanding of these processes on the atomic scale is required. This work is an important step in this direction.

Explore further: Research group discovers nano-crystals at the interface between two liquids

More information: www.pnas.org/cgi/doi/10.1073/pnas.1301800110

Related Stories

Exploring middle ground of solids and liquids

November 16, 2012

(Phys.org)—In experiments at SLAC National Accelerator Laboratory's Linac Coherent Light Source X-ray laser, researchers made snapshots of atomic-scale fluctuations in liquids and glasses. The results are a first step toward ...

Surface structure controls liquid spreading

April 24, 2013

Researchers at Aalto University have developed a purely geometric surface structure that is able to stop and control the spreading of liquids on different types of surfaces. The structure has an undercut edge that works for ...

Materials scientists watch electrons 'melt'

November 22, 2011

(PhysOrg.com) -- When a skier rushes down a ski slope or a skater glides across an ice rink, a very thin melted layer of liquid water forms on the surface of the ice crystals, which allows for a smooth glide instead of a ...

How to overcome the oxide barrier

May 13, 2013

(Phys.org) —Researchers at Pacific Northwest National Laboratory have uncovered the characteristics of a low-resistance electrical contact to strontium titanate, SrTiO3, an important prototypical oxide semiconductor. Oxides ...

Recommended for you

Walking crystals may lead to new field of crystal robotics

February 23, 2018

Researchers have demonstrated that tiny micrometer-sized crystals—just barely visible to the human eye—can "walk" inchworm-style across the slide of a microscope. Other crystals are capable of different modes of locomotion ...

Recurrences in an isolated quantum many-body system

February 23, 2018

It is one of the most astonishing results of physics—when a complex system is left alone, it will return to its initial state with almost perfect precision. Gas particles, for example, chaotically swirling around in a container, ...

Seeing nanoscale details in mammalian cells

February 23, 2018

In 2014, W. E. Moerner, the Harry S. Mosher Professor of Chemistry at Stanford University, won the Nobel Prize in chemistry for co-developing a way of imaging shapes inside cells at very high resolution, called super-resolution ...

Hauling antiprotons around in a van

February 22, 2018

A team of researchers working on the antiProton Unstable Matter Annihilation (PUMA) project near CERN's particle laboratory, according to a report in Nature, plans to capture a billion antiprotons, put them in a shipping ...

Urban heat island effects depend on a city's layout

February 22, 2018

The arrangement of a city's streets and buildings plays a crucial role in the local urban heat island effect, which causes cities to be hotter than their surroundings, researchers have found. The new finding could provide ...

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.