Daniel Miracle talks with
ScienceWatch.com and answers a few questions about
this month's New Hot Paper in the field of Materials
Article Title: The efficient cluster packing model
- An atomic structural model for metallic
Journal: ACTA MATER
Year: SEP 2006
* USAF, Res Lab, Mat & Mfg Directorate, 2230 10th St,
Wright Patterson AFB, OH 45433 USA.
* USAF, Res Lab, Mat & Mfg Directorate, Wright
Patterson AFB, OH 45433 USA.
(addresses have been truncated)
Why do you think your paper is highly
A vibrant international effort has been underway for many years in the
understanding, development, and application of metallic glasses. This paper
describes the atomic structure of metallic glasses, which is important for
nearly every aspect of metallic glass research.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
"I think of
metallic glasses as a
They’re in common use, but
very few of us realize that
we’re using metallic glasses.
Current applications include
anti-theft metal strips on items
from CDs (look inside the raised
plastic UPC label) to fur coats;
corrosion-resistant coatings for
The efficient filling of space is an issue of intense, longstanding
interest. Over the centuries, a great deal of effort has been spent to
describe the way in which spheres can most efficiently fill space. This
problem impacts fields as diverse as cosmology, soil compaction,
agriculture, communication theory, packaging, and the atomic structure of
solids, where atoms try to minimize the space they fill. This paper
combines ideas from mathematics, physics, and chemistry to come up with a
fundamentally new approach for the efficient packing of unequal spheres.
Would you summarize the significance of your paper
in layman’s terms?
The atomic structure of materials controls their properties and behavior. A
clear description of atomic structure not only allows scientists to
understand properties, it also guides efforts to control and improve
materials—from semiconductors, to magnets, to biological and optical
and structural materials. The atomic structure is known in great detail for
nearly all advanced materials, but the structure of metallic glasses has
remained a mystery since they were first discovered over 45 years ago.
While some details remain unresolved, this paper gives the first simple,
physically-based model for the atomic structure of metallic glasses. This
model has improved the ability to develop new metallic glasses, and is also
providing a foundation from which more complete scientific knowledge of
metallic glasses can be obtained.
How did you become involved in this research, and
were there any problems along the way?
This paper describes a structure with a strange co-existence of atomic
order and disorder. This combination challenges expectations that a
structure should be either ordered or disordered—one or the
other—but not both at the same time. This apparent contradiction has
made communication and acceptance of the idea a little more challenging
Where do you see your research leading in the
I’m interested in applying this structural model to gain a fuller
understanding of the stability and deformation of metallic glasses.
Do you foresee any social or political
implications for your research?
There's a better chance of cultural and commercial impacts. I think of
metallic glasses as a “stealth” technology. They’re in
common use, but very few of us realize that we’re using metallic
glasses. Current applications include anti-theft metal strips on items from
CDs (look inside the raised plastic UPC label) to fur coats;
corrosion-resistant coatings for razors; hinges on all those little mirrors
in digital projectors; low-loss magnetic transformers; and high-tech golf
The biggest barriers to more extensive use are the ability to produce
metallic glasses in bulk, and the ability to fundamentally change the way
they deform. A good understanding of the atomic structure has the potential
overcome these barriers.
Dr. Daniel B. Miracle
Materials and Manufacturing Directorate
Air Force Research Laboratory
Wright-Patterson AFB, OH, USA