Hts Logo

NIST High Temp. Superconducting Materials (HTS) Database:

NIST Standard Reference Database 62

Last Update to Data Content: 1996

DOI: https://doi.org/10.18434/T4KP8J

Bibliographic Information

Title: Structure and Oxygen Stoichiometry in Tl2Ba2Ca3Cu4O12-δ A High-Resolution Powder Neutron-Diffraction Study
Author(s): D.M. Ogborne and M.T. Weller
Publication: Physica C Volume: 223 Issue: Not Available Year: 1994 Page(s): 283-290
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature, Magnetic Susceptibility

Materials and Properties

Tl:2234; [Tl-Ba-Ca-Cu-O]
Material Specification for Tl:2234; [Tl-Ba-Ca-Cu-O] Process: Solid State Reaction
Notes: "Powders of Tl2O3, BaO2, CaO and CuO were mixed with a starting metal ratio of Tl:Ba:Ca:Cu=1.5:2:3.5:4 and ground in an agate mortar. The mixed reactants were sealed in gold tubes of 9 mm diameter and calcined at 860 °C for 20 h to 30 h in air with several regrinds. The product was split into three samples each of approximately 7 g, two of which were subsequently annealed: one in a flow of argon at 500 °C for 24 h (Ar), the second in oxygen (0.1 MPa = 1 atm) at 500 °C for 50 h (Ox), and the third received no further treatment (as-prepared). All reactions and annealings were followed by a slow cool to room temperature..."
Formula: Tl2Ba2Ca3Cu4O12-x
Informal Name: Tl:2234
Chemical Family: Tl-Ba-Ca-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Crystallography for Tl:2234; [Tl-Ba-Ca-Cu-O] iv class="table-responsive">
Crystal System: Tetragonal
Formula Units per Cell:
Space Group: I4/mmm
Cell Parameters
Annealing Environment () Occupancy () Temp K a Å b Å c Å
As-prepare --- 296 3.85013(1) -- 41.9839(2)
Oxygen --- 296 3.85049(1) -- 41.9668(2)
Argon --- 296 3.84973(1) -- 42.0421(2)
Atomic Coordinates
Annealing Environment () Occupancy () Atom Temp K a-axis b-axis c-axis
As-prepare 0.541(6) Tl 296 0.5 0.5 0.22561(8)
As-prepare 0.4 Ca 296 0.5 0.5 0.22561(8)
As-prepare -- Ba 296 0.0 0.0 0.1605(1)
As-prepare 0.9 Ca(1) 296 0.0 0.0 0.0
As-prepare 0.1 Tl(1) 296 0.0 0.0 0.0
As-prepare 0.85 Ca(2) 296 0.0 0.0 0.0774(1)
As-prepare 0.15 Tl(2) 296 0.0 0.0 0.0774(1)
As-prepare -- Cu(1) 296 0.5 0.5 0.03837(8)
As-prepare -- Cu(2) 296 0.5 0.5 0.11342(8)
As-prepare -- O(1) 296 0.5 0.0 0.03770(7)
As-prepare -- O(2) 296 0.5 0.0 0.11278(7)
As-prepare -- O(3) 296 0.5 0.5 0.1783(1)
As-prepare 0.245(8) O(4) 296 0.5918(25) 0.5 0.2680(2)
Oxygen 0.534 Tl 296 0.5 0.5 0.22554(8)
Oxygen 0.4 Ca 296 0.5 0.5 0.22554(8)
Oxygen -- Ba 296 0.0 0.0 0.1610(2)
Oxygen 0.9 Ca(1) 296 0.0 0.0 0.0
Oxygen 0.1 Tl(1) 296 0.0 0.0 0.0
Oxygen 0.85 Ca(2) 296 0.0 0.0 0.0775(1)
Oxygen 0.15 Tl(2) 296 0.0 0.0 0.0775(1)
Oxygen -- Cu(1) 296 0.5 0.5 0.03852(9)
Oxygen -- Cu(2) 296 0.5 0.5 0.11348(9)
Oxygen -- O(1) 296 0.5 0.0 0.03773(9)
Oxygen -- O(2) 296 0.5 0.0 0.11271(8)
Oxygen -- O(3) 296 0.5 0.5 0.1785(2)
Oxygen 0.250(9) O(4) 296 0.5887(31) 0.5 0.2680(2)
Argon 0.535 Tl 296 0.5 0.5 0.22481(8)
Argon 0.4 Ca 296 0.5 0.5 0.22481(8)
Argon -- Ba 296 0.0 0.0 0.1607(1)
Argon 0.9 Ca(1) 296 0.0 0.0 0.0
Argon 0.1 Tl(1) 296 0.0 0.0 0.0
Argon 0.85 Ca(2) 296 0.0 0.0 0.0772(1)
Argon 0.15 Tl(2) 296 0.0 0.0 0.0772(1)
Argon -- Cu(1) 296 0.5 0.5 0.03771(9)
Argon -- Cu(2) 296 0.5 0.5 0.11286(9)
Argon -- O(1) 296 0.5 0.0 0.03783(6)
Argon -- O(2) 296 0.5 0.0 0.11288(6)
Argon -- O(3) 296 0.5 0.5 0.1786(1)
Argon 0.237(6) O(4) 296 0.5904(21) 0.5 0.2689(2)
Measurement Method: Neutron diffraction
"Neutron-diffraction data were collected on the High-Resolution Powder Diffractometer (HRPD) on ISIS at the Rutherford Appleton Laboratory. Samples of mass 7 g were placed in vanadium cans and data collected in back-scattering at the 1 m position over the time-of-flight (TOF) range 30000 µs to 120000 µs corresponding to a d spacing range or 0.6126 σ to 2.4862 σ. Data were collected at room temperature for times of approximately 12 h for each sample. The raw data were normalised and corrected for absorption. Visual inspection of the data showed a few weak reflections which, by consideration of d spacing values, were found to arise from CaO. The reflections arising from the impurity phase were not excluded from the refinement but were simultaneously refined with those from the Tl2Ba2Ca3Cu4O12 phase."

Cautions: Evaluated Data
Critical Temperature for Tl:2234; [Tl-Ba-Ca-Cu-O]
Annealing Environment () Critical Temperature (K)
As-prepared 114
Oxygen 109
Argon 106
Measurement Method: Ac susceptibility
"The superconducting properties were measured by AC susceptibility in the temperature range 70 K to 300 K." No additional measurement details were noted.

Cautions: Unevaluated Data
Magnetic Susceptibility for Tl:2234; [Tl-Ba-Ca-Cu-O]
Annealing Environment () Temperature (K) Magnetic Susceptibility (arbitrary)
As-prepared 72 -0.99
As-prepared 80 -0.93
As-prepared 90 -0.84
As-prepared 97 -0.75
As-prepared 100 -0.72
As-prepared 103 -0.59
As-prepared 106 -0.39
As-prepared 107 -0.18
As-prepared 108 -0.08
As-prepared 110 -0.04
As-prepared 112 -0.02
As-prepared 114 0.00
As-prepared 116 0.00
As-prepared 120 0.00
Oxygen 74 -0.99
Oxygen 75 -0.99
Oxygen 80 -0.95
Oxygen 85 -0.90
Oxygen 90 -0.85
Oxygen 95 -0.77
Oxygen 97 -0.72
Oxygen 100 -0.65
Oxygen 102 -0.60
Oxygen 104 -0.37
Oxygen 105 -0.19
Oxygen 105 -0.11
Oxygen 106 -0.07
Oxygen 108 -0.06
Oxygen 109 0.00
Oxygen 115 0.00
Oxygen 120 0.00
Argon 78 -1.00
Argon 81 -1.00
Argon 85 -0.95
Argon 91 -0.84
Argon 94 -0.75
Argon 96 -0.51
Argon 97 -0.22
Argon 98 -0.13
Argon 98 -0.09
Argon 100 -0.06
Argon 103 -0.03
Argon 106 0.00
Argon 110 0.00
Argon 120 0.00
Measurement Method: Ac susceptibility
"The superconducting properties were measured by AC susceptibility in the temperature range 70 K to 300 K." No additional measurement details were noted.

Cautions: Unevaluated Data
Digitized data were obtained from Figure 3 of the paper.