Table Of ContentXIV Introduction
Introduction
1 Subject matter
Subvolume III/21e is the fifth and last one of a series of subvolumes belonging to Landolt-Börnstein, New
Series, Vol. III/21, entitled "Superconductors: Transition Temperatures and Characterization of Elements,
Alloys and Compounds".
The subvolume III/21e presented herewith contains a complete compilation of the superconducting
data of the elements Tl ... Zr, and alloys and compounds based on these elements. The compilation com-
prises not only transition temperatures of more than 4600 substances, but also the preparation technique,
the thermal history, the crystal structure and the lattice parameters. By adding a particular column with the
title "Other properties", it is aimed to give a complete information about the low temperature properties of
a given substance. All available quantitative values of the electronic specific heats, the Debye tempera-
ture, the critical fields and their initial slopes have been included after a critical selection. Other low
temperature physical properties measured on a given substance are indicated. Where available, low
temperature data of proven nonsuperconductors have been included, indicating in each case the lowest
temperature of investigation. Available and confirmed data in subvolume III/21e are included up to 1987.
2 General remarks on the contents of subvolumes III/21a...21e
21a: Superconductors based on Ac...Na
21b: Superconductors based on Nb...Np
21c: Superconductors based on O (without cuprates)...Sc
21d: Superconductors based on Se...Ti
21e: Superconductors based on Tl...Zr
Subvolume 21e contains all available data on the elements Tl...Zr and the alloys and compounds based on
these elements (all the oxides found prior to 1987, without the high T cuprates).
c
3 Selection, arrangement and sequence of the specific data in the tables
a) Selection of the data
The tables include informations on experimental data obtained on
− bulk materials
− thin films
− junctions
(only included if the primary result is a further characterization of the superconducting material, i.e.
energy gap, phonon spectrum or superconductivity by proximity. Superconducting devices are not
included)
− multilayers, superlattices
− granular superconductors
− mono- or multifilamentary wires
(only the material properties are retained, not the configuration. Complex conductors or magnet
characteristics are not included)
Landolt-Börnstein
New Series III/21e
Introduction XV
b) Arrangement of the data
The data in the tables are arranged in individual columns.
Column 1: Number
Column 2: Material
The composition of all alloys has been indicated in atomic percent. The compounds are listed either with
their general compound formula as quoted in the original publication or by their effective composition in
atomic percent (for compositions within a range). The position of the formulae in the table follows their
corresponding composition in atomic percent.
Examples:
− Nb Al Nb based compound, listed under Nb
3
− Ag Sb Ag based alloy, listed under Ag
0.59 0.41
− Ag Pt Alloys or compounds within a range of composition
0.95...0.66 0.05...0.34
− AgLa Equiatomic compound, listed under Ag
− AlFe (10...300 ppm) Dilute alloy
− Al (H, Impl) Al, implanted with hydrogen
− Nb/Al O /Pb Junction, indicating the sequence of metal/insulator/metal
2 3
− Nb/Ta Bilayer or multilayer or superlattice
The sequence of the various substances is fixed by following rules:
−the elements are listed in alphabetical order,
−the alloys and compounds are listed in the alphabetical order of the base element, i.e. the element with
the highest concentration in atomic percent,
−within the same base element, the binary alloys and compounds are listed in the alphabetical order and
increasing concentration of the second constituent,
−tenary alloys and compounds are first listed in alphabetical order of the base element. Within the same
base element, the further listing occurs in alphabetical order of the element with the second highest
concentration, and so on.
Examples: Cu0.35Al0.45Si0.20 and BaPb1−xBixO3 will be found under the base elements Al and O,
respectively.
Column 3: Characterization
The morphology of the sample, the preparation method and the thermal history are described in this column.
i) Morphology, modification and shape of the samples
Bul, 5N+ Bulk configuration. For bulk elements, the purity has been indicated where
available, e.g. 6N = 0.999999 (1 ppm impurities), 5N4 = 0.999994,
5N+ = better than 0.99999
Film (200 nm on Al O ) Thin film configuration. Where available, the film thickness and the
2 3
Lay (5 µm on Cu) substrate material are given. The distinction between film and layer being not
always clear, the notation used by the respective authors is used
Pow (50 µm) Powder with 50 µm average particle size. If the shape of the powders is of im-
portance, e.g. spherical, this is indicated by Pow (50 µm, sphere)
Tape Self-supporting tape produced by splat cooling or rolling or coating of the
superconductor on a metallic tape
Foil (0.1 mm) Self-supporting superconducting foil
Wire (0.2 mm) Wire or rod, with indication of the diameter
Wire (5 µm) Monofilamentary wire, with the diameter of the superconducting filament
Landolt-Börnstein
New Series III/21e
XVI Introduction
MFil or Wire (720 . 5 µm) Multifilamentary wire configuration, obtained by repeated stacking of rods
and deformation of the billets by extrusion and wire drawing. In parentheses,
number and diameter of the superconducting filaments
Whi Whiskers
Mono (2 . 3 . 5 mm3) Single crystal. Where available, the size is given
Poly Polycrystal. Polycrystalline bulk oxides are often characterized as ceramics
Gran (3 µm, Al O ) Granular material. The size of the superconductor and the nature of the
2 3
insulating matrix are specified
MLay (...) Multilayer. The thickness of various materials can vary and must be specified,
as well as the number of the layers
SuLa (20 nm, 200 nm) Superlattice. In a periodically alternating sequence of layers constituting a
superlattice, the layer thickness of the two constituents is given.
(For example: Al, 20 nm, Fe, 200 nm)
Eut Eutectic alloys
HOPG Highly oriented pyrolytic graphite
ii) Sample preparation
Mel Melted, without particular precisions
ArcM Arc melted
SplC Splat cooled. If available, the initial temperature and the foil thickness are
given
MelSp Produced by melt spinning. If available, the rotating speed and the tape
thickness are given
ZMel Zone melted
In Situ Melting procedure of mutually almost insoluble elements, leading to dendrite
growth (for example, Nb dendrites in Cu). Subsequent deformation to a wire
leads to a large number of elongated dendrites of 10...1000 nm thickness, thus
constituting a multifilamentary configuration
P/M Powdermetallurgical approach for producing a multifilamentary configura-
tion. Powder mixtures of 20...200 µm particle size are mixed, compressed and
drawn to fine wires, each powder particle being elongated to filaments with
thickness of 10...1000 nm (example: Cu − 20wt% Nb P/M mixtures)
Sint (800 K/20 h) Sintered at 800 K for 20 hours
HP (5 GPa, 1200 K/1 h) Hot pressed at 5 GPa and 1200 K for 1 hour
Flux Flux grown
Subl Sublimated
Evap Evaporated
Coev Coevaporated. If available, substrate material and temperature as well as
pressure are indicated
Spu (500 K, Al O ) Films produced by sputtering on an Al O substrate held at 500 K. If
2 3 2 3
available, indications about gas mixture and pressure are given
ReSpu (800 K, MgO, N ) Reactively sputtered film on a MgO substrate held at 800 K in a reactive N
2 2
atmosphere
CVD Chemical vapor deposition. If available, the reaction conditions are given
Epi Epitaxial deposition. The kind of epitaxial deposition is indicated in
parentheses:
− MBE: molecular beam epitaxy
− VPE: vapor phase epitaxy
ElDep Electrodeposited. Particular conditions are given in the "Remarks"
QC (10 K) Quench condensed at 10 K
DiffR (973 K/64 h) Diffusion reaction at 973 K for 64 hours
Impl (20 keV/32S) Produced by implantation of 32S ions at energies of 20 keV
Landolt-Börnstein
New Series III/21e
Introduction XVII
iii) Material history
Q Quenched, without further indication
WQ Water quenched
OQ Oil quenched
LGQ Liquid gas quenched, e.g. N , Ar
2
ArJQ Argon jet quenched
Ann (1070 K/20 h) Annealed at 1070 K for 20 hours
ThMec Thermomechanical heat treatment (alternating sequence of deformation and
annealing)
CW Cold worked, stays also for "strained"
Irr (1 MeV, 3.1015 n/cm2 , Irradiated with neutrons of 1 MeV energy at 150 K
T = 150 K)
irr
iiii) Technical details about wire preparation
MFil Multifilamentary configuration in a wire, obtained by repeated stacking of
rods and deformation of the billets by extrusion and wire drawing. A large
number of filaments with diameters between 5 and 10 (cid:181)m leads to a higher
thermal, electrical and mechanical stability.
In Situ A wire with multifilamentary configuration can be obtained by using the
In Situ technique, a melting procedure leading to dendrite growth of one
component into the other. If both components are ductile (for example, V
dendrites in Cu), deformation to a wire leads to a large number of elongated
dendrites, thus constituting a multifilamentary configuration. For example, a
Cu/V rod produced by the In Situ technique is first Ga coated, then reacted to
V Ga.
3
Dip The superconducting layer is obtained by dipping a V substrate tape or a V
rod in an appropriate liquid Ga bath. The resulting surface layer is submitted
to a reaction heat treatment at T > 1200 K which renders it superconducting.
Bronze The A15 phase V Ga in a superconducting wire is formed by a solid state
3
diffusion process, the so-called "bronze diffusion process", where the Ga
contained in a Cu-Ga bronze matrix diffuses to the V filaments and reacts
there around 923 K to V Ga. Due to the severe work hardening of the Cu-Ga
3
bronze, this technique requires a large number of intermediate recovery heat
treatments during wire formation.
Column 4: Crystal structure, a, c [[[[nm]]]]
Am amorphous
Tetr tetragonal
bct, fct body centered tetragonal, face centered tetragonal
Cub cubic
bcc, fcc body centered cubic, face centered cubic
Hex hexagonal
hcp hexagonal close packed
dhcp double hexagonal close packed
Ortho orthorhombic
Mono monoclinic
Rhomb, rh rhombohedral
Tricl triclinic
In cases where the crystal structure has been analyzed, the structure type is given, e.g. W, Cr Si,
3
PbMo S , ...
6 8
Landolt-Börnstein
New Series III/21e
XVIII Introduction
In parentheses, the "Strukturbericht" notation is indicated for the structures where it has been defined.
Examples: W (A2)
Mg (A3)
Cr Si (A15)
3
Ni Sn (D0 )
3 19
PbMo S
6 8
NdRh B
4 4
(See section 5 Alphabetical list of frequently used structure types.)
If a material is not single phased, the crystal structure corresponding to the superconducting phase will be
printed in bold types. If a material consists of two superconducting phases, the crystal structure will be
indicated after T (see column 5).
c
The lattice parameters for cubic and tetragonal phases are listed in column 4. For all other structure
types with 2 and more lattice parameters, the values of the latter are given in the "Remarks".
Column 5: Superconducting transition temperatures T ;T [[[[K]]]]
c n
In this column, the transition temperatures of proven superconductors are listed, but also the lowest
temperature of investigation of interesting materials where no superconductivity was found.
Examples:
12.0 Reported value of T for accepted or confirmed values of T . Cases where further
c c
confirmation is needed are described in the "Remarks"
4.6 (A3); 7.5 (A15) The material consists of two superconducting phases with T = 4.6 K and 7.5 K,
c
respectively
<0.032n The material is normal or nonsuperconducting above 0.032 K, the lowest
temperature attained in the investigation
2.7...6.2 T is measured over a composition range, 2.7 and 6.2 K being the T values at both
c c
composition limits, for example at 0.10 and 0.35 at% of the element B in the range
A B . The detailed variation of T in this range with possible maxima or
0.90...0.65 0.10...0.35 c
minima is described in the "Remarks"
0.245, Reentr Reentrant superconductor. The corresponding ferromagnetic transition (for example,
at T = 0.241 K) will be indicated in the "Remarks"
ferro Ferromagnetic material
antiferro Aniferromagnetic material
100 MPa: 0.3
200 MPa: 0.6 T as a function of applied hydrostatic pressure
c
450 MPa: <0.4n
0.05, Extr T has been extrapolated from a series of measurements at various compositions
c
not given T is not given in the paper, but the substance is a proven superconductor and the
c
data on other physical properties than T are of interest
c
Column 6: Other properties
In this column, all the physical properties treated in the analyzed paper in addition to T are mentioned.
c
The symbols for the physical quantities are given in the list of symbols and abbreviations.
Column 7: Remarks
The experimental values of the electronic specific heat, the Debye temperature, and the critical fields are
given in this column. The values of many other properties, e.g. the Curie temperature and the Néel
temperature, are also explicitly given.
Landolt-Börnstein
New Series III/21e
Introduction XIX
Column 8: References
The first two numbers of the reference key indicate the year of publication of books, papers, conference
proceedings and patents. The following three letters are an abbreviation of the first author’s name, and the
number at the end of the reference key is a serial number and allows an unequivocal distinction between
several papers. For Russian articles, the reference key corresponds to the publication year of the Russian
original. Where available, the English translation of the article has been added, too.
In order to save space in the handbook, the references for the Low Temperature Conferences No. 1 to
18 have been written in an abbreviated version, e.g. LT-1, Vol.3 (1975) 45. The full text comprising
editors, publishers, year of publication, etc. for all the LT conferences up to 1987 is listed below.
International Conference on Low Temperature Physics (Proceeding)
LT-1 International Conference on Low Temperature Physics, 1st, 1949
Cambridge 6.−10.9.1949
in Physics today 2 (1949) No. 11.
LT-2 International Conference on Low Temperature Physics, 2nd, 1951
Oxford 22.−28.8.1951.
Bowers, R. (ed.), Oxford: Clarendon Press, 1951.
LT-3 International Conference on Low Temperature Physics and Chemistry, 3rd, 1953
Houston, Texas 17.−22.10.1953.
LT-4 Conférence de Physique des Basses Températures, 4th, 1955
Paris 2.−8.9.1955
in Annexe 1955-3, Supplément au Bulletin de l’Institut International du Froid.
LT-5 International Conference on Low Temperature Physics and Chemistry, 5th, 1957
Madison, Wisconsin 26.−31.8.1957
Dillinger, J.R. (ed.), Madison: The University of Wisconsin Press, 1958.
LT-6 International Conference on Low Temperature Physics, 6th, 1958
Leiden 23.−28.6.1958
in Achives Néerlandaises des Sciences Exactes et Naturelles, Ser. 4A, Suppl. 24 (1958) No.9.
LT-7 International Conference on Low Temperature Physics, 7th, 1960
Toronto, Canada 29.8.−3.9.1960
Graham, G.M., Hollis Hallett, A.C. (eds.), Toronto: University of Toronto Press, 1961.
LT-8 International Conference on Low Temperature Physics, 8th, 1962
London 16.−22.9.1962
Davies, R.O. (ed.), London: Butterworth & Co., 1963.
LT-9 International Conference on Low Temperature Physics, 9th, 1964
Columbus, Ohio, 31.8.−4.9.1964
Daunt, J.G., Edwards, D.O., Milford, F.J., Yaqub, M. (eds.), New York: Plenum Press, 1965.
Part A pages 1−620
Part B pages 621−1255.
LT-10 International Conference on Low Temperature Physics, 10th, 1966
Moskau
Malkov, M.P. (ed.), Moskau, 1967.
LT-11 International Conference on Low Temperature Physics, 11th, 1968
St. Andrews, Scotland 21.−28.8.1968
Allen, J.F., Finlayson, D.M., McCall, D.M. (eds.), St. Adrews: The University of St. Andrews
Printing Department, 1968.
Vol. 1 Plenary Papers
Sect. A 4He, 3He and mixtures
Sect. D Experimental Methods and other Low Temperature Phenomena
Vol. 2 Sect. B Superconductivity
Sect. C Normal Metals and Magnetic Ordering.
Landolt-Börnstein
New Series III/21e
XX Introduction
LT-12 International Conference on Low Temperature Physics, 12th, 1970
Kyoto, Japan 4.−10.9.1970
Kanda, E. (ed.), Tokyo, Japan: Keigaku Publishing Co., LTD., 1971.
LT-13 International Conference on Low Temperature Physics, 13th, 1972
Boulder, Colorado 21.−25.8.1972
Timmerhaus, K.D., O’Sullivan, W.J., Hammel, E.F. (eds.), New York: Plenum Press, 1974.
Vol. 1 Quantum Fluids
Vol. 2 Quantum Crystals and Magnetism
Vol. 3 Superconductivity
Vol. 4 Electronic Properties, Instrumentation and Measurement.
LT-14 International Conference on Low Temperature Physics, 14th, 1975
Otaniemi, Finland 14.−20.8.1975
Krusius, M., Vuorio, M. (eds.), Amsterdam: North-Holland Publishing Company, 1975.
Vol. 1 Helium
Vol. 2 Superconductivity
Vol. 3 Low Temperature Properties of Solids
Vol. 4 Techniques and Special Topics
Vol. 5 Invited and Post-Deadline Papers.
LT-15 International Conference on Low Temperature Physics, 15th, 1978
Grenoble, France 23.−29.8.1978
Tournier, R. (ed.), Orsay: Editions de Physique 1978 in
Journal de Physique (Paris) Colloque 39 (1978) C6.
Vol. 1 Quantum Fluids and Solids
Superconductivity
Vol. 2 Low Temperature Properties of Solids
Techniques
Vol. 3 Invited Papers.
LT-16 International Conference on Low Temperature Physics, 16th, 1981
Los Angeles 19.−25.8.1981
Clark, W.G. (ed.), Amsterdam: North-Holland, 1981.
Vol. 1 Physica 107 B + C (1981) 1−750
Vol. 2 Physica 108 B + C (1981) 751−1390
Vol. 3 Physica 109/110 B + C (1982) 1391−2220.
LT-17 International Conference on Low Temperature Physics, 17th, 1984
Karlsruhe 15.−22.8.1984
Eckern, U., Schmid, A., Weber, W., Wühl, H. (eds.), Amsterdam: North-Holland, 1984.
Vol. 1 Contributed Papers
Vol. 2 Contributed Papers
Vol. 3 Invited Papers and Post-Deadline Papers in Physica 126 B + C (1984) Nos. 1-3,
p. 1−526.
LT-18 International Conference on Low Temperature Physics, 18th, 1987
Kyoto 20.−26.8.1987
Nagaoka, Y. (ed.), Japanes Journal of Applied Physics 26 (1987) Suppl. 26-3.
Vol. 1 Quantum Liquids and Solids
Low Temperature Properties of Solids
Vol. 2 Superconductivity
Techniques and Application.
Landolt-Börnstein
New Series III/21e
Introduction XXI
c) Sequence of the substances in the tables
Within the same base element, the substances are listed by their modification, starting with "element,
bulk", followed by "elements under pressure", "thin films", ... as indicated below. Within the same
modification, the sequence of substances is then given by the physical properties.
1. Element, bulk
The data are listed in the sequence:
− Transition temperature only, without other physical properties
− Specific heat data (priority)
− Critical field data
− Other physical properties
Within these criteria, all materials are listed following the reference symbol, in inverse chronological
order (the last year first) and alphabetical order of the author’s name.
2. Element, under pressure
The data are listed with increasing pressure, then following year and author’s name.
3. Thin films, deposited at T > 77 K
The data are listed in the sequence:
− T only, without other physical properties
c
− Specific heat data (priority)
− Critical field data
− Other physical properties
Within these criteria, all materials are listed in the order of increasing film thickness, followed by
those where film thickness is not given (listed following year and author’s name).
4. Thin films, deposited at T ≤ 77K
Same sequence as for films deposited at T > 77 K.
5. Multilayers, superlattices
6. Granular films
Listed with increasing superconducting particle diameter, followed by the materials where the
granule diameter is not given (listed following year and author’s name).
7. Junctions
Within a base element in alphabetical order of the second element.
8. Dilute alloys
Solute element in alphabetical order with increasing concentration.
9. Implantation
Implanted element in alphabetical order.
10.Composites
Listed in alphabetical order and increasing concentration of the matrix element.
11.Alloys and compounds
For alloys and compounds based on the element A:
−binaries A1−xBx or AaBb with alphabetical order and increasing concentration of the element B
−ternaries A1−x−yBxCy or AaBbCc with alphabetical order and increasing concentration of the element
with the second highest concentration, then element with the lowest concentration in alpabetical
order and increasing concentration.
Landolt-Börnstein
New Series III/21e
XXII Introduction
4 List of symbols and abbreviations
Symbols Units Definitions
〈a2〉 Energy gap anisotropy parameter
a Crystallographic analysis at room temperature
0
a (p) nm Lattice parameter vs. hydrostatic pressure
0
a (T) nm Lattice parameter vs. temperature
0
a (φ t) nm Lattice parameter vs. radiation fluence
0
ac losses kJ m−3 Hysteretic alternating current (ac) losses
A Number of atoms per unit cell
Age Ageing effects
Andr Andreev reflexion
Auger or AES Auger spectroscopy analysis
b (or h) Reduced magnetic field: b = B/B = H/H , where H is the
c2 c2 c2
upper critical magnetic field and B = µH
c2 0 c2
B T Magnetic induction, B = µµH, with µ ≈ 1: B = µH
0 0
c, c(T) mJ/K gat Specific heat capacity vs. temperature
c(H) mJ/K mol Specific heat capacity under an applied magnetic field
c N m−2 Elastic constants
ij
c ,c m s−1 Sound velocity
l t
C mJ K−1 mol−1 Normal part of the electronic specific heat
en
C mJ K−1 mol−1 Superconducting part of the electronic specific heat
es
Cavity Superconducting cavities
CDW Charge density waves
Channel Channeling experiments
d kg m−3 Density
d µm Thickness (of samples)
d nm Critical thickness of films
cr
D m2 s−1 Diffusion coefficients
Decor Decoration experiments for visualization of flux lines
Def Mechanical deformation
Defect Defect or vacancy analysis
DOS Density of states curves
DSC Differential scanning calorimetry
DTA Differential thermal analysis
dHvA De Haas-van Alphen effect
E GPa Young’s modulus
E eV Fermi energy
F
ED Electron diffraction analysis
EDX Energy dispersive X-ray spectroscopy
EELS Electron energy loss spectroscopy
EPMA Electron probe microanalysis
EPR Electron paramagnetic resonance
ESR Electron spin resonance
Ett Ettingshausen effect
EXAFS Extended X-ray analysis of fine structures
F N m−3 Bulk pinning force
p
F (H), F (h) N m−3 Bulk pinning force, as a function of the applied field
p p
FC Flux creep investigations
FF Flux flow considerations
Landolt-Börnstein
New Series III/21e
Introduction XXIII
Symbols Units Definitions
FIR Far infrared reflectivity
Fluc Fluctuation behaviour
FL Flux line lattice
F(ω ) Hz−1 True phonon density of states
g g factor
G(r) m−1 Atomic distribution function
G(ω ) Hz−1 Generalized phonon density of states
Galv General symbol for galvanomagnetic effects other than Ett,
R , See, ...
H
h (or b) h = H/H (0)
c2
H a) Magnetic field strength
H a) Breakdown field
b
H , H (T) a) Thermodynamic critical field strength vs. temperature
c c
H a) H = H (0)
0 0 c
H (p) a) H vs. pressure
c c
H (d) a) H vs. film thickness
c c
Hc ||, Hc⊥ a) Anisotropy of Hc with respect to a given crystallographic
orientation
dH /dT b) Initial slope of H (T) at T
c c c
H , H (T) a) Lower critical magnetic field strength vs. temperature
c1 c1
H (p) a) H vs. pressure
c1 c1
H (d) a) H vs. film thickness
c1 c1
Hc1 ||, Hc1⊥ a) Anistropy of Hc1 with respect to a given crystallographic
orientation
dH /dT b) Initial slope of H (T) at T
c1 c1 c
H , H (T) a) Upper critical magnetic field strength vs. temperature
c2 c2
H (p) a) H vs. pressure
c2 c2
H (d) a) H vs. film thickness
c2 c2
Hc2||, Hc2⊥ a) Anistropy of Hc2 with respect to a given crystallographic
orientation
H (ϑ) a) Angular dependence of H
c2 c2
dH /dT b) Initial slope of H (T) at T
c2 c2 c
H||, H⊥ a) Anistropy of Hc1 or Hc2 (not specified) with respect to a given
crystallographic orientation
H* a) Upper critical magnetic field at 4.2 K as extrapolated using the
c2
Kramer plot
H* (T) a) Upper critical magnetic field strength at a given temperature
c2
T ≠ 4.2 K as extrapolated using Kramer plot
H a) Critical magnetic field strength where the surface
c3
superconductivity vanishes
H a) Nucleation field
n
H Vickers microhardness
v
HRTM High resolution transmission electron microscopy
a) The physical property indicated in the column "other properties" is H, the magnetic field strength,
with the unit [A m−1]. The quantitative values in the "Remarks" are given in [T], the unit of the
magnetic induction B = µH.
0
b) Same remark as for a), but for the units [A m−1 K−1] and [T K−1]. The full notation for the initial field
slope would be !! $!" , but has been simplified in the tables for practical reasons.
"# " ="
"
Landolt-Börnstein
New Series III/21e
