NIST High Temp. Superconducting Materials (HTS) Database

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: Yb(Ba,Sr)₂Cu₄O₈: A "124" Phase Superconductor with a Reduced Unit Cell Volume
Author(s): Y. Yaegashi, S. Adachi, T. Wada, S. Takano, and H. Yamauchi
Publication: Physica C Volume: 190 Issue: Not Available Year: 1992 Page(s): 433-436
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Crystallography, Critical Temperature, Resistivity (normal state), Magnetic Susceptibility

Materials and Properties

Yb:124; [Yb-Ba(Sr)-Cu-O]

Material Specification for Yb:124; [Yb-Ba(Sr)-Cu-O] Process: Solid State Reaction
Notes: "The Yb(Ba_1-xSr_x)₂Cu₄O_x samples were prepared employing a conventional solid-state reaction method and a hot isostatic pressing (HIP) technique. High purity powders (99.9%) of Yb₂O₃, BaCO₃, SrCO₃ and CuO were used as starting materials... appropriate amounts of powders in the nominal compositions of Yb(Ba_1-xSr_x)₂Cu₄O₈ (0.0 ≤x ≤0.5) were mixed and pressed. The lump mixtures were calcined at 900 °C for 20 h in O₂ gas flow and then ground. The calcined powder was pressed into parallelepiped bars and pre-sintered at 920 °C in flowing O₂ gas. The compacted bars were sintered and annealed at 1070 °C for 6 h in a mixed gas, 80% Ar+20% O₂, of a high pressure of 200 MPa..."
Formula: YbBa_2-xSr_xCu₄O₈
Informal Name: Yb:124
Chemical Family: Yb-Ba(Sr)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Crystallography for Yb:124; [Yb-Ba(Sr)-Cu-O]

Crystal System:	Orthorhombic
Formula Units per Cell:
Space Group:

**Cell Parameters**
x of Sr_x (formula units)	Temp K	a Å	b Å	c Å
0.2	296	3.814(1)	3.857(1)	27.129(1)
0.4	296	3.805(1)	3.855(1)	27.072(1)
0.6	296	3.796(1)	3.851(1)	27.022(1)
0.8	296	3.794(1)	3.851(1)	27.007(1)

Measurement Method: X-ray diffraction
"The lattice parameters were determined by X-ray powder diffraction using CuK α radiation." No additional measurement details were noted.

Cautions: Unevaluated Data

Critical Temperature for Yb:124; [Yb-Ba(Sr)-Cu-O]

x of Sr_x (formula units)	T_c(magnetic) (K)	T_c(onset) (K)	Critical Temperature (K)
0.2	80	82	77
0.4	80	83	78
0.6	80	83	77
0.8	80	81	76

Measurement Method: Four-probe method
"The electrical resistivity of the samples were measured by a conventional DC four-probe method." No additional measurement details were noted.

Cautions: Unevaluated Data

Resistivity (normal state) for Yb:124; [Yb-Ba(Sr)-Cu-O]

x of Sr_x (formula units)	Temperature (K)	Resistivity (normal state) (mΩ·cm)
0.2	50	0.0
0.2	77	0.0
0.2	81	0.6
0.2	84	1.2
0.2	125	2.0
0.2	175	2.9
0.2	225	3.5
0.2	275	4.0
0.4	50	0.0
0.4	78	0.0
0.4	83	0.8
0.4	125	1.3
0.4	175	1.9
0.4	225	2.2
0.4	275	2.7
0.6	50	0.0
0.6	77	0.0
0.6	81	1.2
0.6	125	2.0
0.6	175	2.7
0.6	225	3.2
0.6	275	3.8
0.8	50	0.0
0.8	76	0.0
0.8	81	2.0
0.8	84	2.3
0.8	125	3.6
0.8	175	4.7
0.8	225	5.6
0.8	275	6.4

Magnetic Susceptibility for Yb:124; [Yb-Ba(Sr)-Cu-O]

x of Sr_x (formula units)	Temperature (K)	Magnetic Susceptibility (arbitrary)
0.2	5	-0.0047
0.2	20	-0.0046
0.2	40	-0.0047
0.2	60	-0.0047
0.2	72	-0.0044
0.2	76	-0.0031
0.2	78	-0.0013
0.2	81	0.0000
0.2	100	0.0000
0.4	4	-0.0049
0.4	20	-0.0049
0.4	40	-0.0049
0.4	60	-0.0049
0.4	74	-0.0042
0.4	78	-0.0018
0.4	81	0.0000
0.4	90	0.0000
0.4	100	0.0000
0.6	5	-0.0041
0.6	21	-0.0041
0.6	40	-0.0041
0.6	60	-0.0041
0.6	74	-0.0035
0.6	78	-0.0013
0.6	80	0.0000
0.6	100	0.0000
0.8	5	-0.0030
0.8	21	-0.0030
0.8	40	-0.0030
0.8	60	-0.0030
0.8	74	-0.0021
0.8	78	-0.0003
0.8	80	0.0000
0.8	100	0.0000

Measurement Method: SQUID magnetometer
"The DC magnetic susceptibility measurements were carried out using a SQUID magnetometer." No additional measurement details were noted.

Cautions: Unevaluated Data
Digitized data were obtained from Figure 4 of the data.