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High-pressure helium gas apparatus and hydrostatic toroid cell for low-temperatures applications
ARTICLE IN PRESS
Physica B 359–361 (2005) 1463–1465 www.elsevier.com/locate/physb
High-pressure helium gas apparatus and hydrostatic toroid cell for low-temperatures applications Alla E. Petrovaa,, Vladimir A. Sidorova, Sergei M. Stishova,b a
Institute for High Pressure Physics, 142190 Troitsk, Moscow Region, Russian Federation b Los Alamos National Laboratory, Los Alamos, NM 87545, USA
Abstract We describe a high-pressure helium-gas apparatus and a hydrostatic toroid cell for low-temperature applications. The first can be used to create very nearly hydrostatic pressures of 1.5 GPa and operate at temperatures less than 2 K for electrical, magnetic and thermodynamic measurements. The toroid cell is a clamped anvil device with a special anvil profile that accepts a Teflon capsule containing a sample and suitable liquid pressure medium. The toroid cell generates pressures to 6 GPa and can be used with any kind of cryostat. r 2005 Elsevier B.V. All rights reserved. PACS: 07.20.Mc; 07.35.+k Keywords: Helium pressure cell; Toroid
Nowadays, many high-pressure experiments at low temperatures employ a clamped piston–cylinder technique. These cells reach typically 3 GPa and, depending on the pressure medium, are more or less hydrostatic. The latter is an important factor that can influence experimental results. We overview briefly two devices that overcome some of these limitations. The high-pressure helium-gas apparatus creates an almost ideal hydrostatic environment for samples at low temperatures in Corresponding author. Tel.: +7 095 334 07 32;
fax: +7 095 334 00 12. E-mail address: [email protected] (A.E. Petrova).
the medium of fluid and solid helium, and the clamped toroid cell, with a 1.5:1 mixture of glycerol and water, allows a nearly hydrostatic environment at pressures up to 6 GPa for resistivity and AC specific heat [1,2]. The helium-gas installation (Fig. 1) consists of an intensifier (1), an inlet hydraulic pressure valve (2), a check valve (3), check valve holder (4), a manganin bomb (5), connector for high pressure tubing (6), high pressure tubing (7), a relieving hydraulic valve (8), and an oil pump with a screw drive (9). The experimental cell (10), made from beryllium bronze with a working volume of 8-mm diameter and 20-mm height, is connected to the
0921-4526/$ - see front matter r 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.physb.2005.01.454
ARTICLE IN PRESS 1464
A.E. Petrova et al. / Physica B 359– 361 (2005) 1463–1465
Fig. 1. High-pressure helium gas apparatus: (1) intensifier, (2) inlet valve, (3) check valve, (4) check valve holder, (5) manganin bomb, (6) connector for high-pressure tubing, (7) high-pressure tubing, (8) relieving valve, (9) oil pump, (10) experimental cell.
installation with a stainless steel capillary (7) that minimizes heat transfer into the cryostat. The installation also contains a gas compressor (not shown), and an oil pump (not shown), which supply hydro cylinders of the intensifier, the inlet and relieving valves. The seal of the intensifier piston, described earlier as an element in installations for compression of fluids [3], also works superbly for the compression of gases if the seal rings are tinned with indium. Otherwise, significant friction, impeding normal operation of the intensifier, develops in the piston pair. Electrical leads introduced through a feedthrough at the bottom of the cell allows for electrical resistivity and related types of measurements. Pressure in the cell is created at room temperature by introducing helium gas compressed to a pressure of about 0.2 GPa [4] that is fed into the installation through valve (2) and then repeatedly compressed by the intensifier (1). A cryostat, described in Ref. [5], has been built and tested for cooling the cell while connected to the high-pressure generator through a stainless
steel capillary. The design of the cryostat ensures easy access to the high-pressure cell and the possibility of removing it without completely warming the cryostat. This gas installation has been used for dilatometric studies of tricritical phenomena in some ferroelectric crystals, like KDP and SbSJ at pressures to 1 GPa. The toroid cell used to generate pressures to 6 GPa at a low temperature is shown in Fig. 2. The cell consists of a clamp (1) and (2), toroidal anvils Ref. [6] with a special profile (3) (see expanded view), spring (4), and bearing plates (5). A gasket (6), made of boron-epoxy or alumina-epoxy mixtures, contains a small Teflon capsule 7 (2.2 mm diameter and 2 mm height) filled with a suitable liquid. Strain gauge measurements show that a 3:2 glycerol–water mixture, which freezes near 6 GPa at room temperature, creates a much more hydrostatic environment than conventionally used mixtures of flourinert. Ten wires going through the gasket to the high-pressure zone make it possible to carry out physical measurements of various kinds. To create pressure, the anvils with a gasket and Teflon capsule are placed in the clamp,
Fig. 2. Hydrostatic toroid cell: (1) body, (2) bolt, (3) toroid anvils, (4) spring, (5) bearing plates.
ARTICLE IN PRESS A.E. Petrova et al. / Physica B 359– 361 (2005) 1463–1465
which is loaded with help of a pushing rod and a hydraulic press under control of a strain gauge. The load is then fixed by a bolt (2), and the cell is transferred to a cryostat and slowly cooled to the base temperature of a cryostat. Pressure at low temperature is measured by observing the superconducting transition of a lead manometer, whose transition width did not exceed 15 mK at 5.5 GPa. The typical pressure drop upon cooling from room to liquid helium temperatures is 0.3–0.4 GPa. The efficiency of this technique was recently demonstrated at studying electrical resistivity of the strongly correlated materials CeCoIn5 and CeAgSb2 in the 5–6 GPa range [1,2]. This work was supported by Russian Foundation for Basic Research (03-02-17119) and special
1465
programs of the Department of Physical Sciences, Russian Academy of Sciences.
References [1] V.A. Sidorov, M. Nicklas, P.G. Pagiuso, et al., Phys. Rev. Lett. 89 (2002) 157004. [2] V.A. Sidorov, E.D. Bauer, N.A. Frederick, et al., Phys. Rev. B 67 (2003) 224419. [3] S.M. Stishov, V.A. Zilberstein, Instrum. Exp. Tech.-U. 4 (1966) 1003. [4] S.M. Stishov, A.F. Uvarov, Instrum. Exp. Tech.-U. 14 (1971) 258. [5] A.E. Petrova, S.M. Stishov, Instrum. Exp. Tech. 47 (2004) 135. [6] L.G. Khvostantsev, L.F. Vereshchagin, A.P. Novikov, High Temp.-High Press. 7 (1977) 637.
Physica B 359–361 (2005) 1463–1465 www.elsevier.com/locate/physb
High-pressure helium gas apparatus and hydrostatic toroid cell for low-temperatures applications Alla E. Petrovaa,, Vladimir A. Sidorova, Sergei M. Stishova,b a
Institute for High Pressure Physics, 142190 Troitsk, Moscow Region, Russian Federation b Los Alamos National Laboratory, Los Alamos, NM 87545, USA
Abstract We describe a high-pressure helium-gas apparatus and a hydrostatic toroid cell for low-temperature applications. The first can be used to create very nearly hydrostatic pressures of 1.5 GPa and operate at temperatures less than 2 K for electrical, magnetic and thermodynamic measurements. The toroid cell is a clamped anvil device with a special anvil profile that accepts a Teflon capsule containing a sample and suitable liquid pressure medium. The toroid cell generates pressures to 6 GPa and can be used with any kind of cryostat. r 2005 Elsevier B.V. All rights reserved. PACS: 07.20.Mc; 07.35.+k Keywords: Helium pressure cell; Toroid
Nowadays, many high-pressure experiments at low temperatures employ a clamped piston–cylinder technique. These cells reach typically 3 GPa and, depending on the pressure medium, are more or less hydrostatic. The latter is an important factor that can influence experimental results. We overview briefly two devices that overcome some of these limitations. The high-pressure helium-gas apparatus creates an almost ideal hydrostatic environment for samples at low temperatures in Corresponding author. Tel.: +7 095 334 07 32;
fax: +7 095 334 00 12. E-mail address: [email protected] (A.E. Petrova).
the medium of fluid and solid helium, and the clamped toroid cell, with a 1.5:1 mixture of glycerol and water, allows a nearly hydrostatic environment at pressures up to 6 GPa for resistivity and AC specific heat [1,2]. The helium-gas installation (Fig. 1) consists of an intensifier (1), an inlet hydraulic pressure valve (2), a check valve (3), check valve holder (4), a manganin bomb (5), connector for high pressure tubing (6), high pressure tubing (7), a relieving hydraulic valve (8), and an oil pump with a screw drive (9). The experimental cell (10), made from beryllium bronze with a working volume of 8-mm diameter and 20-mm height, is connected to the
0921-4526/$ - see front matter r 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.physb.2005.01.454
ARTICLE IN PRESS 1464
A.E. Petrova et al. / Physica B 359– 361 (2005) 1463–1465
Fig. 1. High-pressure helium gas apparatus: (1) intensifier, (2) inlet valve, (3) check valve, (4) check valve holder, (5) manganin bomb, (6) connector for high-pressure tubing, (7) high-pressure tubing, (8) relieving valve, (9) oil pump, (10) experimental cell.
installation with a stainless steel capillary (7) that minimizes heat transfer into the cryostat. The installation also contains a gas compressor (not shown), and an oil pump (not shown), which supply hydro cylinders of the intensifier, the inlet and relieving valves. The seal of the intensifier piston, described earlier as an element in installations for compression of fluids [3], also works superbly for the compression of gases if the seal rings are tinned with indium. Otherwise, significant friction, impeding normal operation of the intensifier, develops in the piston pair. Electrical leads introduced through a feedthrough at the bottom of the cell allows for electrical resistivity and related types of measurements. Pressure in the cell is created at room temperature by introducing helium gas compressed to a pressure of about 0.2 GPa [4] that is fed into the installation through valve (2) and then repeatedly compressed by the intensifier (1). A cryostat, described in Ref. [5], has been built and tested for cooling the cell while connected to the high-pressure generator through a stainless
steel capillary. The design of the cryostat ensures easy access to the high-pressure cell and the possibility of removing it without completely warming the cryostat. This gas installation has been used for dilatometric studies of tricritical phenomena in some ferroelectric crystals, like KDP and SbSJ at pressures to 1 GPa. The toroid cell used to generate pressures to 6 GPa at a low temperature is shown in Fig. 2. The cell consists of a clamp (1) and (2), toroidal anvils Ref. [6] with a special profile (3) (see expanded view), spring (4), and bearing plates (5). A gasket (6), made of boron-epoxy or alumina-epoxy mixtures, contains a small Teflon capsule 7 (2.2 mm diameter and 2 mm height) filled with a suitable liquid. Strain gauge measurements show that a 3:2 glycerol–water mixture, which freezes near 6 GPa at room temperature, creates a much more hydrostatic environment than conventionally used mixtures of flourinert. Ten wires going through the gasket to the high-pressure zone make it possible to carry out physical measurements of various kinds. To create pressure, the anvils with a gasket and Teflon capsule are placed in the clamp,
Fig. 2. Hydrostatic toroid cell: (1) body, (2) bolt, (3) toroid anvils, (4) spring, (5) bearing plates.
ARTICLE IN PRESS A.E. Petrova et al. / Physica B 359– 361 (2005) 1463–1465
which is loaded with help of a pushing rod and a hydraulic press under control of a strain gauge. The load is then fixed by a bolt (2), and the cell is transferred to a cryostat and slowly cooled to the base temperature of a cryostat. Pressure at low temperature is measured by observing the superconducting transition of a lead manometer, whose transition width did not exceed 15 mK at 5.5 GPa. The typical pressure drop upon cooling from room to liquid helium temperatures is 0.3–0.4 GPa. The efficiency of this technique was recently demonstrated at studying electrical resistivity of the strongly correlated materials CeCoIn5 and CeAgSb2 in the 5–6 GPa range [1,2]. This work was supported by Russian Foundation for Basic Research (03-02-17119) and special
1465
programs of the Department of Physical Sciences, Russian Academy of Sciences.
References [1] V.A. Sidorov, M. Nicklas, P.G. Pagiuso, et al., Phys. Rev. Lett. 89 (2002) 157004. [2] V.A. Sidorov, E.D. Bauer, N.A. Frederick, et al., Phys. Rev. B 67 (2003) 224419. [3] S.M. Stishov, V.A. Zilberstein, Instrum. Exp. Tech.-U. 4 (1966) 1003. [4] S.M. Stishov, A.F. Uvarov, Instrum. Exp. Tech.-U. 14 (1971) 258. [5] A.E. Petrova, S.M. Stishov, Instrum. Exp. Tech. 47 (2004) 135. [6] L.G. Khvostantsev, L.F. Vereshchagin, A.P. Novikov, High Temp.-High Press. 7 (1977) 637.