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A simple uniaxial high pressure cell for electrical resistivity measurements
PHYSICA ELSEVIER
Physica C 341-348 (2000) 1559-1560 www.elsevier.nl/locate/physc
A Simple Uniaxial High Pressure Cell for Electrical Resistivity Measurements S.Arumugam and N.Mori Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8581, Japan A new simple uniaxial high-pressure cell has been developed to measure electrical resistivity simultaneously for three superconducting crystals upto 5 kbar. The Tc of L a 1 . s 5 S r 0 . 1 5 C u O 4 superconducting crystal was measured along a-, c - and (110) axes and shows an increase, a decrease and no effect with increasing pressure respectively.
1.
INTRODUCTION In a hydrostatic pressure, the unit cell is compressed simultaneously along three axes by an amount proportional to the compressibility of each axis. However, under uniaxial pressure, the unit cell is compressed in only one direction and expands in other two directions. In particular, the uniaxial pressure effect should yield more information on the anisotropic coupling of the structure and superconductivity along three crystallographic directions. Most of the highpressure experiments were carried out on high Tc materials either hydrostatic or quasi-hydrostatic pressure [1-7], only few measurements were reported on uniaxial pressure technique [2-7]. The uniaxial pressure was calculated indirectly from different experiments like thermal expansion, magnetic field induced grain alignment and strained thin films [4-6]. In this paper, we describe a newly developed a simple uniaxial high pressure cell for electrical resistivity measurements simultaneously for three samples, by direct method upto 5 kbar. As an example the pressure effect on Tc of L a l . s s S r 0 . 1 5 C u O 4 superconducting crystal along a-, c- and (110) axes is presented [2].
of the sample and the load applied through the spring. The pressure was always applied at room temperature. The accuracy in the pressure measurement is less than 0.01kbar. The body of the cell and the anvils were made of copper and the hardened Cu-Be alloy respectively.
Micrometer
-- Spring
2. U N I A X I A L P R E S S U R E D E V I C E The cross-sectional view of the uniaxial high pressure setup is shown in Fig.1. The pressure was applied through a high strength steel spring attached with a micrometer and the pressure is maintained at all temperatures from 300 K to the low temperature. By choosing the different spring constant value of the spring, the maximum pressure can be varied. The pressure was calculated directly from the surface area
I......4 3 mm
Fig.1. A cross-sectional view of the uniaxial pressure experimental setup for electrical resistivity measurements. The electrical resistivity measurements were carried out with minimum of one sample to maximum of three samples simultaneously, by varying the thickness of
0921-4534/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII S0921-4534(00)01334-4
1560
S. Arumugam. l~ Mori/P/o,sica C 3 4 1 - 3 4 8 (2000) 1559-1560
the anvils. The dimensions of the crystal were - 1.5 x 1.5x 1.8 mm3, along a-, b- and c- axes, respectively. The contacts were made by gold paints and then annealed in an appropriate temperature under oxygen atmosphere. These gold contacts on the sample were connected by gold wire with silver paints. The contacts were more reliable and show the resistance < 0.2 f2 ohms at all temperatures. We have used four-probe method for electrical resistivity measurements to eliminate the contact resistance. The temperature was measured with Pt-Co and Ru-O thermometers directly and attached to the pressure cell in two different places with general Electric varnish. 3. UNIAXIAL PRESSURE EFFECT ON Tc The temperature dependence of resistivity at various pressures for a-a, c-c and (110) samples of Lal.ssSr0asCuO4 single crystal is shown in Fig. (2a,b &c) [2]. The Tc along a-, c - and (110) axes shows an increase (dTc /dP,, = +0.3 K/kbar), a decrease (dTc/dP~= -0.19 K/kbar) and no effect with increasing pressure respectively (Fig. 2a,b &c). 0.08
C
0.04
o~-
v° %
o.
,,~ o~ 03
36
o
P=O kbar
+ o
P=0.4 kba] P=0.8 kbal
" 38
P=I. 2kbax
13tal3~tat-~
+-+-H-
-
+ • ee vv ooo o I:1 + • ×~evvvO ooo o° El+a xe v oo El 4- • × • vv o°
0
0.4
o.
El + "× •v o 0.~i~- El÷+**×. v o* m~* × ~ v o° L- n + . x • v o
El +
•
×xe°v
o
] ] / [
u . A × • v" o ~
• x " v o
42
,
,
,
,
,
i
i
,
,
-
o +
_~g
i o~v~ ~fl'J
~
0
o
J
I
~
,
*
,
I
i
i
42
i
• +
P=O kbar P=0.2 kbal P=0.4kbar P=0.6 kba P=l.2kbar 44
TtK) Fig.2c. The temperature dependence of the electrical resistivity of LaLssSr0asCuO4 at various pressures for (110) sample [2]. 4.CONCLUSION This is one of the simplest ways to measure electrical resistivity under direct uniaxial pressure technique and it can be extended to measure other transport properties such as magnetoresistance.
REFERENCES 40
4_++++
i
/
0.8
=L "-'~m 0.4 Q.
J
(llO)
ACKNOWLEDGMENTS This study was supported by grant-in-aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan. SA was supported by Post Doctoral Fellowship from Japan Society for the Promotion of Science.
~-o ¢-o
cI
, --
P=0.8 kbar~ P=l.6kbar]~ P=2 kbar ~ P=2"4 kbarH P=2.S kbar~ P=3.5 kbar 44
T (K)
Fig.2 (a & b). The temperature dependence of the electrical resistivity of L a L s s S r 0 A 5 C u O 4 at various pressures for a-a and c-c samples [2].
[1] H. Takahashi and N. Mori, in Studies of High Temperature superconductors, Ed.A.V.Narlikar, 16,1, Nova.Sci. Pub. 1997. [2]. S. Arumugam, N.Mori, N.Takeshita, H.Takashima, H. Eisaki and S. Uchida, Phys.Rev.Lett.1999 (Communicated). [3] S. Arumugam, N.Mori, N.Takeshita, H.Takashima, T.Noda, H.Eisaki and S.Uchida (In the same issue). [4] Y. Motoi, K. Fujimoto, H. Uwe, and T. Sakudo, J. of Phys. Soc. of Jpn. 60(2), 384 (1991. [5] H. Tabata, T. Kawai, and S. Kawai, Phys. Rev. Lett. 70(17), 2633 (1993). [6] C. Meingast, F. Gugeneberger, O. Kraut, and H. Wuhl, Physica 235-240C, 1313 (1994). [7] U. Welp, M. Grimsditch, S. Fleshier, J. Nestler, J. Downey, G. W. Crabtree, and J. Guimpel, Phys. Rev. Lett. 69(14), 2130 (1992).
Physica C 341-348 (2000) 1559-1560 www.elsevier.nl/locate/physc
A Simple Uniaxial High Pressure Cell for Electrical Resistivity Measurements S.Arumugam and N.Mori Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8581, Japan A new simple uniaxial high-pressure cell has been developed to measure electrical resistivity simultaneously for three superconducting crystals upto 5 kbar. The Tc of L a 1 . s 5 S r 0 . 1 5 C u O 4 superconducting crystal was measured along a-, c - and (110) axes and shows an increase, a decrease and no effect with increasing pressure respectively.
1.
INTRODUCTION In a hydrostatic pressure, the unit cell is compressed simultaneously along three axes by an amount proportional to the compressibility of each axis. However, under uniaxial pressure, the unit cell is compressed in only one direction and expands in other two directions. In particular, the uniaxial pressure effect should yield more information on the anisotropic coupling of the structure and superconductivity along three crystallographic directions. Most of the highpressure experiments were carried out on high Tc materials either hydrostatic or quasi-hydrostatic pressure [1-7], only few measurements were reported on uniaxial pressure technique [2-7]. The uniaxial pressure was calculated indirectly from different experiments like thermal expansion, magnetic field induced grain alignment and strained thin films [4-6]. In this paper, we describe a newly developed a simple uniaxial high pressure cell for electrical resistivity measurements simultaneously for three samples, by direct method upto 5 kbar. As an example the pressure effect on Tc of L a l . s s S r 0 . 1 5 C u O 4 superconducting crystal along a-, c- and (110) axes is presented [2].
of the sample and the load applied through the spring. The pressure was always applied at room temperature. The accuracy in the pressure measurement is less than 0.01kbar. The body of the cell and the anvils were made of copper and the hardened Cu-Be alloy respectively.
Micrometer
-- Spring
2. U N I A X I A L P R E S S U R E D E V I C E The cross-sectional view of the uniaxial high pressure setup is shown in Fig.1. The pressure was applied through a high strength steel spring attached with a micrometer and the pressure is maintained at all temperatures from 300 K to the low temperature. By choosing the different spring constant value of the spring, the maximum pressure can be varied. The pressure was calculated directly from the surface area
I......4 3 mm
Fig.1. A cross-sectional view of the uniaxial pressure experimental setup for electrical resistivity measurements. The electrical resistivity measurements were carried out with minimum of one sample to maximum of three samples simultaneously, by varying the thickness of
0921-4534/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII S0921-4534(00)01334-4
1560
S. Arumugam. l~ Mori/P/o,sica C 3 4 1 - 3 4 8 (2000) 1559-1560
the anvils. The dimensions of the crystal were - 1.5 x 1.5x 1.8 mm3, along a-, b- and c- axes, respectively. The contacts were made by gold paints and then annealed in an appropriate temperature under oxygen atmosphere. These gold contacts on the sample were connected by gold wire with silver paints. The contacts were more reliable and show the resistance < 0.2 f2 ohms at all temperatures. We have used four-probe method for electrical resistivity measurements to eliminate the contact resistance. The temperature was measured with Pt-Co and Ru-O thermometers directly and attached to the pressure cell in two different places with general Electric varnish. 3. UNIAXIAL PRESSURE EFFECT ON Tc The temperature dependence of resistivity at various pressures for a-a, c-c and (110) samples of Lal.ssSr0asCuO4 single crystal is shown in Fig. (2a,b &c) [2]. The Tc along a-, c - and (110) axes shows an increase (dTc /dP,, = +0.3 K/kbar), a decrease (dTc/dP~= -0.19 K/kbar) and no effect with increasing pressure respectively (Fig. 2a,b &c). 0.08
C
0.04
o~-
v° %
o.
,,~ o~ 03
36
o
P=O kbar
+ o
P=0.4 kba] P=0.8 kbal
" 38
P=I. 2kbax
13tal3~tat-~
+-+-H-
-
+ • ee vv ooo o I:1 + • ×~evvvO ooo o° El+a xe v oo El 4- • × • vv o°
0
0.4
o.
El + "× •v o 0.~i~- El÷+**×. v o* m~* × ~ v o° L- n + . x • v o
El +
•
×xe°v
o
] ] / [
u . A × • v" o ~
• x " v o
42
,
,
,
,
,
i
i
,
,
-
o +
_~g
i o~v~ ~fl'J
~
0
o
J
I
~
,
*
,
I
i
i
42
i
• +
P=O kbar P=0.2 kbal P=0.4kbar P=0.6 kba P=l.2kbar 44
TtK) Fig.2c. The temperature dependence of the electrical resistivity of LaLssSr0asCuO4 at various pressures for (110) sample [2]. 4.CONCLUSION This is one of the simplest ways to measure electrical resistivity under direct uniaxial pressure technique and it can be extended to measure other transport properties such as magnetoresistance.
REFERENCES 40
4_++++
i
/
0.8
=L "-'~m 0.4 Q.
J
(llO)
ACKNOWLEDGMENTS This study was supported by grant-in-aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan. SA was supported by Post Doctoral Fellowship from Japan Society for the Promotion of Science.
~-o ¢-o
cI
, --
P=0.8 kbar~ P=l.6kbar]~ P=2 kbar ~ P=2"4 kbarH P=2.S kbar~ P=3.5 kbar 44
T (K)
Fig.2 (a & b). The temperature dependence of the electrical resistivity of L a L s s S r 0 A 5 C u O 4 at various pressures for a-a and c-c samples [2].
[1] H. Takahashi and N. Mori, in Studies of High Temperature superconductors, Ed.A.V.Narlikar, 16,1, Nova.Sci. Pub. 1997. [2]. S. Arumugam, N.Mori, N.Takeshita, H.Takashima, H. Eisaki and S. Uchida, Phys.Rev.Lett.1999 (Communicated). [3] S. Arumugam, N.Mori, N.Takeshita, H.Takashima, T.Noda, H.Eisaki and S.Uchida (In the same issue). [4] Y. Motoi, K. Fujimoto, H. Uwe, and T. Sakudo, J. of Phys. Soc. of Jpn. 60(2), 384 (1991. [5] H. Tabata, T. Kawai, and S. Kawai, Phys. Rev. Lett. 70(17), 2633 (1993). [6] C. Meingast, F. Gugeneberger, O. Kraut, and H. Wuhl, Physica 235-240C, 1313 (1994). [7] U. Welp, M. Grimsditch, S. Fleshier, J. Nestler, J. Downey, G. W. Crabtree, and J. Guimpel, Phys. Rev. Lett. 69(14), 2130 (1992).