He Turned Up The Heat On a Very Cold Subject
Murray Hill, N.J. (June, 1997) -- Bertram Batlogg looks up at
pictures mounted high on his office walls of the mountains surrounding
Bludenz, the small Austrian city where he grew up. Then he says somewhat
wistfully, "Every mountain has its own character, distinct shape,
distinct color, and there is a distinct way to climb it."
The Bell Labs physicist and world-renowned superconductivity expert
then lifts a framed picture of a germanium copper oxide crystal that had
been perched atop a cabinet and says, "It's the same way with
these materials. Each and every material has its own character. The way
we deal with it, the way it functions, and the way we have to think
"These materials, particularly if they are grown in the form of
crystals...are aesthetically appealing. They have shiny surfaces, they
have special shapes, corners, and very often great colors. Look at these
blue colored crystals," he continues pointing to the picture as
though it were a great work of art. "I find it most
There are also striking similarities between
his love of the challenges of mountain climbing and skiing and
the fulfillment Batlogg
clearly derives from his striving to master these crystals by coaxing
them to reveal the secrets of their superconductive characteristics.
What makes these crystals, and certain other materials,
superconductive is their ability to lose all electrical resistance when
cooled to below their critical temperatures. And while rapid fire
advancements have caused these temperatures to rise quickly over the
past several years, they are still cold enough to make the winter
temperatures on Batlogg's beloved mountain peaks seem like the
When he came to Bell Labs in 1979 as a post doctoral fellow from the
Swiss Federal Institute of Technology in Zurich, Batlogg planned to stay
a year or two and return to his homeland.
"Less than a year passed and my department head came into my lab
and casually asked if I wanted to stay a little bit longer," he
It was a difficult decision, because he was anxious to get back to
Austria, but after consulting with his family, he decided to stay. That
was 18 years ago. "I got used to not having the mountains in front
of my office windows any more," he said. These days he skis the
Rockies more often than the Alps.
Seven years after joining Bell Labs, Batlogg was named head of the
Solid State and Physics of Materials Research Department. The year was
1986 and all was relatively quiet in the small, esoteric world of
superconducting science. But then, near the end of that year, an
announcement was made that was the superconducting equivalent of a sonic
A material was discovered that would soon lead to the breaking of
what Batlogg called, "the famous 77-degree barrier."
Seventy-seven degrees Kelvin (K), or -320° F, is the point at which
nitrogen, the primary constituent of air, becomes a cryogenic liquid. In
the world of superconductivity that had been downright hot. Prior to the
breaking of that barrier the materials known to be superconducting had
to be chilled down to 23K (-418° F), or close to absolute zero. To
achieve that temperature required the use of rare and precious liquid
helium. Liquid nitrogen, on the other hand, is plentiful and relatively
A plume of vapor rises as Bertram Batlogg
prepares to fire up a superconducting magnet by piping in liquid helium
at -452° F.
The breakthrough that led to the shattering of the 77-degree barrier
was made by two scientists working at an IBM laboratory near Zurich, who
Batlogg knew from his college days. Their discovery that copper oxide
materials could become superconductive at unprecedentedly high
temperatures gave birth to the field known as "high temperature
superconductivity," or High Tc for short.
"We were hovering around 23 degrees for many years, then came
this family of copper oxide materials," said Batlogg. "It
began a worldwide revolution in the field."
At Bell Labs, Batlogg and Bob Cava, another superconductivity expert,
and their colleagues immediately began investigating copper oxides.
"In no time we defined a better material than originally reported.
This gave us a really flying start," said Batlogg.
Advances at Bell Labs and elsewhere came in rapid succession. Within
a few months new copper oxide materials were developed that had
transition temperatures well above 77K.
"Nowadays copper oxide is superconducting at around 160 degrees
Kelvin [-168° F], which is halfway up to room temperature,"
says Batlogg, "and our part was quite significant in these
Meanwhile, the expectations for High Tc created by the copper oxide
discoveries opened the floodgates to the small and sequestered world of
superconductivity research. "There was an uninhibited
enthusiasm," said the Bell Labs physicist, who along with Cava, was
thrust into the limelight.
A NOVA television crew virtually lived with them for a
week. They were also quoted extensively in articles about
superconductivity appearing in Time and Life
magazines, U.S. News & World Report, and the
London Press, to mention a few.
Although high temperature superconductors have yet to live up to
their billing during those heady days of the late 1980s, they hold great
promise for fields ranging from electronics to power transmission and
With superconductivity electric utilities could transmit power more
efficiently; electronic equipment could be smaller and higher
performing; and large magnets can be made extremely powerful and
One of the most widespread practical applications of such supercooled
magnets is in magnetic resonance imaging (MRI) machines used in the
medical field to view internal organs without the risks of X-rays.
Work at Bell Labs dating back to the 1960s was instrumental in the
successful scientific and engineering development of superconducting
technology. " Bell Labs has a splendid history of making major
discoveries in the field of superconductivity," says Batlogg. Much
of the early work was done by Bernd Matthias, who "was a world
leading expert in developing new materials, always with the quest of
finding those that would be superconducting at higher and higher
temperatures....he was one of our Bell Labs heroes."
In fact, the International Conference on Materials and Mechanism of
Superconductivity created a Bernd Matthias Prize which this year was
bestowed on Batlogg and Cava, for their "leading work in a variety
One of their most important contributions was the discovery of
precisely what it is that imparts High Tc characteristics to the copper
oxide material first found to have that capability. Until then it was
only known that copper oxides were High Tc materials, but not what
combination of elements made them such.
"We came up with the right recipe," says Batlogg. It was a
formula that came to be known as the 'one-two-three' compound...for one
barium, two yttriums, three coppers, and seven oxygens."
This discovery came at a time when the excitement over High Tc led to
an intensity of work that Batlogg says was amazing. "We would spend
shifts here, working day and night."
Being well aware of the need to quickly publish their one-two-three
findings Batlogg and his colleagues prepared a patent application in a
day, and decided to write a paper on the subject that same night.
"We sat down around 10 o'clock. I called my wife, she delivered
two bottles of hot coffee, probably the strongest coffee I've ever had,
and a fresh sheet of corn bread," said Batlogg, who lives within
walking distance of his office. "The next time we turned around it
was 6 a.m. The paper was written, and the coffee was gone, but we were
alive and ready to go to the lab -- apparently the coffee did its
The resulting paper was published in Physical Review
During this period the Bell Labs scientists also began to focus on
the applicability of superconductivity to telecommunications, and
determined that microwave transmissions presented an opportunity.
Microwave filters using this technology have since been developed and
are now being tested.
In another field, Batlogg is working on the development of organic
semiconductors while continuing to investigate classes of materials
similar to copper oxide that hold promise for yet higher temperature
superconductivity. The goal of the superconductivity work is to develop
a "general understanding of how the materials function, what makes
them function the way they do, and to learn how to prepare them and
manipulate them in a way this is beneficial for practical
applications" explains Batlogg.
And never far from his mind is the thought of finding a material that
is superconducting at room temperature or above. That, says Batlogg,
undoubtedly reminiscing about the 77- degree-barrier days, "would
capture the imagination."
As for if and when that may happen, the physicist alludes to a
mountain climbing dictum as he says, "You can never predict
breakthroughs. But you better be ready when they occur."
When the barrier was broken, he notes, "We were ready. We seized
the opportunity, and we contributed solid science. This is one of the
hallmarks of Bell Labs. We have scientists here who have a broad and
deep understanding. And even if they don't make the discovery firsthand,
we have the people to seize the opportunity and go with it, and adapt it
to our purposes, and that's what happened with High Tc."