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: High Pressure Study on La_2-xSr_xCuO₄ Near x = 0.12
Author(s): C.W. Chu, Q. Xiong, J.W. Chu, Y.Y. Sun, H.H. Feng, S. Bud'ko and P.H. Hor
Publication: HTS Materials, Bulk Processing and Bulk Applications Volume: Not Available Issue: Not Available Year: 1992 Page(s): 117-122
Editor(s): C.W. Chu, W.K.Chu, P.H. Hor,and K. Salama
Publisher: World Scientific
Language: English
Notes: Proceedings of the 1992 TCSUH Workshop, February 27-28, 1992
Keywords: Material Specification, Critical Temperature, Resistivity (normal state)

Materials and Properties

La:21; [La(Sr)-Cu-O]

Material Specification for La:21; [La(Sr)-Cu-O] Process: Solid State Reaction
Notes: "The standard solid state reaction technique was used to prepare all samples studied here. Mixtures of appropriate amounts of La₂O₃, SrCO₃ and CuO were fired at 1273 K to 1353 K in air for about two weeks with intermittent grinding once a day. The products were then compacted and heat-treated for two more days at 1173 K in one atmospheric pressure of O₂ before being slow-cooled to 300 K at a rate of (about) 0.4 K/min... A microprobe was used to determine the gross composition of x. Samples with fine steps of x were prepared by diluting samples of greater x successively."
Formula: La_2-xSr_xCuO₄
Informal Name: La:21
Chemical Family: La(Sr)-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Critical Temperature for La:21; [La(Sr)-Cu-O]

x of Sr_x (formula units)	Pressure (GPa)	Critical Temperature (K)
0.075	0.0	24.0
0.075	4.4	24.2
0.075	9.2	25.0
0.075	11.5	25.4
0.075	14.9	25.9
0.1	0.3	32.2
0.1	1.6	32.4
0.1	5.6	33.3
0.1	9.5	34.3
0.1	14.5	35.8
0.11	0.0	28.7
0.11	1.7	28.7
0.11	5.9	28.9
0.11	9.7	29.8
0.11	14.5	30.6
0.14	0.0	38.7
0.14	6.2	39.1
0.14	11.6	40.5
0.14	15.2	40.9
0.16	0.0	36.6
0.16	3.7	36.9
0.16	8.1	37.9
0.16	13.4	38.4

Measurement Method: Four-probe method
"Samples of dimensions of (about) 4x1x0.5 mm³ were cut from the pellets for resistive measurements using a four-lead technique... The temperature was measured using a chromel-alumel thermocouple or a germanium thermometer in various ranges with an uncertainty ≤ 1% in the temperature region of interest to the present investigation. The high pressure environment was provided by a modified Be-Cu high-pressure-clamp technique, using the 3M fluorinert fluid as the pressure medium. The pressure was measured by a superconducting Pb-manometer placed next to the sample inside the high pressure cell."

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

Resistivity (normal state) for La:21; [La(Sr)-Cu-O]

x of Sr_x (formula units)	Pressure (GPa)	Temperature (K)	Resistivity (normal state) (mΩ·cm)
0.11	0.00	28	0.01
0.11	0.00	29	0.11
0.11	0.00	30	0.32
0.11	0.00	30	0.52
0.11	0.00	33	0.72
0.11	0.00	50	0.84
0.11	0.00	62	0.87
0.11	0.00	74	0.89
0.11	0.59	29	0.01
0.11	0.59	30	0.12
0.11	0.59	30	0.32
0.11	0.59	31	0.52
0.11	0.59	35	0.72
0.11	0.59	50	0.81
0.11	0.59	61	0.84
0.11	0.59	75	0.88
0.11	0.99	30	0.01
0.11	0.99	31	0.12
0.11	0.99	32	0.52
0.11	0.99	38	0.73
0.11	0.99	50	0.79
0.11	0.99	62	0.82
0.11	0.99	75	0.85
0.11	1.48	30	0.01
0.11	1.48	31	0.11
0.11	1.48	31	0.32
0.11	1.48	33	0.52
0.11	1.48	40	0.72
0.11	1.48	50	0.77
0.11	1.48	61	0.79
0.11	1.48	75	0.82