Journal ArticleDOI

# Germanium telluride: specific heat and superconductivity

17 Aug 1964-Physical Review Letters (American Physical Society)-Vol. 13, Iss: 7, pp 233-234

Topics: Germanium telluride (70%), Superconductivity (52%)

Content maybe subject to copyright    Report

Lawrence Berkeley National Laboratory
Recent Work
Title
GERMANIUM TELLURIDE: SPECIFIC HEAT AND SUPERCONDUCTIVITY
https://escholarship.org/uc/item/6fk8r321
Author
Finegold, Leonard.
Publication Date
1964-07-01
University of California

UCRL-11534
University of California
Ernest
0.
Lawrence
Laboratory
TWO-WEEK
LOAN
COPY
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is
a
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Circulating
Copy
which
may
be
borrowed
for
two
weeks.
For
a
personal
retention
copy,
call
Tech.
Info.
Division,
Ext.
5545
GERJ\.1ANIUM
TELLURIDE:
SPECIFIC
HEAT
AND
SUPERCONDUCTIVITY
Berkeley, California

DISCLAIMER
This document was prepared
as
an account
of
work sponsored by the United States
Government. While this document is believed
to
contain correct information, neither the
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of
the University of
California, nor any
of
their employees, makes any warranty, express or implied, or
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of
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information, apparatus, product, or process disclosed, or represents that its use would not
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GERMANIUM
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Leonard
Finegold
July
1964
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According
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L.
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theoretical
predictions,
certa~
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t
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semiconductors
and
semimetals
may be.
superconductors
at
experi-
·;
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·
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mentally
accessible
temperatures.
He
in
et
al.
have
examined germanium'·· . ,
·,,
·
·.
: _ .
;_
..
-.
.
tel_luride
containing
a
large
number
of
car:riers.
.
They
find
that
it
does.
'' -
··
· ·
. . . .
~
:
·:,
indeed
show
those
changes:\in
magnetic
s'usceptibility
with
temperature
~o
·
::;···.·'
.
be
expected
of
a
superconductor.
However,
susceptibility
(and
.resisti-
_-
. :; .
vity)
mea_surements do
not
·exclude
the
possibility
of.
the
superconducti-
vity
being
confined
to
unrepresentative
regions
of
the
sample
(Hein
et
,I·_,
'•
..
al.).
The
heat
capacity
measurements
presented
here
show
that
at
least
· · . · : ·
·'
·
the
major
part
of
the
germanium
telluride
sample
was
superconducting,
and
hence
.that
the
superconductivity
observed
by
Hein
et
al.
is
a
true
:
''.
,.
bulk
effect.
,(
:
"'-,._
:
~
..
,
·'
-~
. .
·-'
..
'.
A
germani~
telluride
sample
of
the
type
used
by
Hein
et
al.
was
·,·.
kindly
supplied
to
me
by
Dr.
J.
K. Hulm.
It
was a
specially
prepared
·
·'
',
k
)
large
(one
grl;llll-mole)
cylinder
of
nominal
composition
Ge.
950
Te,
annealed·
,
....
'•
..
for
ten
days
at
485°C.
Attached
to
the
sample
were
a
carbon
(painted
-·,
·_:
· ·-: ·
·;
f :
colloidal
graphit~)
resistance
thermometer,
manganin
heater,
copper,
-
··
',
~-
varnish,
and'a
negiigibie
amount
(<.0.001
mole)
of
in
a
super-
'
conducting
heat
switch
•.
The
apparatus
was
that
described
by
O'Neal
and
,'· .
Phillips
3
For
each
series
of
heat
capacity
measu;rements,
the
·sample·
.
.>
.
:--
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.:
i
'f._
.......
-··-·"
.....
_
..
' '
'-.
;'··.•.
.
-.
~
~
~-,
'
::
..
:,_·

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