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E D Adams - One of the best experts on this subject based on the ideXlab platform.
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Realization of the ^3He Melting Pressure Scale, PLTS-2000
Journal of Low Temperature Physics, 2007Co-Authors: R. L. Rusby, Laurent Pitre, E D Adams, Bernd Fellmuth, J. Engert, W. E. Fogle, M. DurieuxAbstract:The Provisional Low Temperature Scale of 2000, PLTS-2000, which was adopted in October 2000, uses the Melting Pressure of ^3He to provide the basis for temperature measurement in the range from the Néel temperature of the solid, T _2000=0.902 mK, up to 1 K. The definition and derivation of the scale has been published, and the present paper now gives guidance on the practical methods by which the Melting Pressures can be measured in the laboratory. Various options are described, depending on the equipment available, and the uncertainties that may be achieved are considered.
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Realization of the 3He Melting Pressure Scale, PLTS-2000
Journal of Low Temperature Physics, 2007Co-Authors: R. L. Rusby, Laurent Pitre, E D Adams, Bernd Fellmuth, J. Engert, W. E. Fogle, M. DurieuxAbstract:The Provisional Low Temperature Scale of 2000, PLTS-2000, which was adopted in October 2000, uses the Melting Pressure of 3He to provide the basis for temperature measurement in the range from the Neel temperature of the solid, T2000=0.902 mK, up to 1 K. The definition and derivation of the scale has been published, and the present paper now gives guidance on the practical methods by which the Melting Pressures can be measured in the laboratory. Various options are described, depending on the equipment available, and the uncertainties that may be achieved are considered.
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The Provisional Low Temperature Scale from 0.9 mK to 1 K, PLTS‐2000
AIP Conference Proceedings, 2003Co-Authors: R. L. Rusby, W. E. Fogle, M. Durieux, A. L. Reesink, R P Hudson, G. Schuster, M. Kühne, R. J. Soulen, E D AdamsAbstract:The Provisional Low Temperature Scale from 0.9 mK to 1 K, PLTS‐2000, was adopted by the Comite International des Poids et Mesures in October 2000. It is defined using an equation for the Melting Pressure of 3He over the complete temperature range, and forms an extension of the International Temperature Scale of 1990, ITS‐90, below its lower limit of 0.65 K. An internationally‐accepted ultra‐low temperature scale is needed to provide the basis for reliable thermometry in the temperature range in which commercial dilution refrigerators operate, and at lower temperatures where experiments investigating the thermodynamic properties of 3He and other condensed matter are carried out in many research centres. This paper is a summary of a fuller publication describing the background and derivation of the scale, published in the Journal of Low Temperature Physics [1], and includes tables of values of Melting Pressure, pm / MPa, and temperature T2000 / K, and the derivative, dpm /dT2000 in MPa/K.
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The formation and Melting of He-3 clusters in phase-separated solid He-3-He-4 mixtures.
Journal of Low Temperature Physics, 1998Co-Authors: Richard P. Haley, E D AdamsAbstract:Melting Pressure measurements have been made on the He-3-rich phase formed by cooling a solid mixture of 0.6% He-3 in He-4 through phase separation, at Pressures between 2.78 and 3.56 MPa. For comparison, simultaneous observations were made with the mixture confined in the pores of a silver sinter and in an open volume connected to the same fill-line. Samples in the sinter cell solidify at higher Pressures than the open cell and equilibrate more quickly. Both cells exhibit hysteresis between Melting and freezing temperatures, and the transitions are broader in the open-volume cell. Relative to pure He-3, the Melting Pressure is elevated by as much as 60 kPa in the sinter cell and 20 kPa in the open cell. The size of the Pressure change on Melting indicates that a large fraction of the He-3 remains solid at Pressures below the Melting curve, and this effect is more pronounced in the sinter cell. Measurements are in progress to measure the magnetisation through the magnetic ordering transition.
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Melting of He-3 in a phase-separated solid He-3-He-4 mixture.
1997Co-Authors: Richard P. Haley, E D AdamsAbstract:The Melting Pressure of the He-3-rich phase, which is formed after phase separation of a mixture of 0.6% He-3 in He-4, has been studied in the temperature range 1-150 mK, below the phase-separation temperature T-ps, at Pressures between 2.78 and 3.56 MPa. Measurements were made with the mixture confined in a silver sinter, and also in an open volume for comparison. An elevation of the Melting Pressure relative to pure He-3 of up to 60 kPa in the sinter cell and 20 kPa in the open-volume cell was observed. Hysteresis between the freezing and Melting temperatures was found for both cells, similar to that observed for pure He-3 in small pores. The results of Schrenk et al. for heat capacity measurements on a similar system are discussed.
Takayoshi Mamiya - One of the best experts on this subject based on the ideXlab platform.
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Specific heat due to amorphous surface layers in liquid and solid 3He
Physica B-condensed Matter, 2000Co-Authors: Hiroshi Kambara, S. Kishishita, Takayoshi MamiyaAbstract:Abstract We have observed an excess specific heat for solid 3 He in silver sinter from Melting Pressure to 55 bar below a few tens of mK. The excess specific heat is nearly independent of temperature. Except for the solid near the Melting Pressure, the magnitude of the excess specific heat is almost constant throughout a wide Pressure region. This fact is explained in terms of the presence of about two layers of amorphous surface solid 3 He on the heterogeneous silver-sinter substrate.
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Specific heat due to amorphous surface in solid 3He
Europhysics Letters (EPL), 1999Co-Authors: Hiroshi Kambara, S. Kishishita, Taku Matsushita, Takayoshi MamiyaAbstract:We have observed an excess specific heat in bcc solid 3He at low temperatures and at Pressures between the Melting Pressure and 46 bar. The excess specific heat is nearly independent of temperature. In the solid just above the Melting Pressure, the magnitude of the anomaly is about 2.5 times larger than that at high Pressures. Except for the solid near the Melting Pressure, the magnitude is constant with Pressure and is nearly the same as that in liquid 3He in Vycor. This anomaly of the specific heat in solid 3He is explained in terms of the amorphous surface solid on a disordered substrate.
Ping Song - One of the best experts on this subject based on the ideXlab platform.
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Melting along the Hugoniot and solid phase transition for Sn via sound velocity measurements
Journal of Applied Physics, 2016Co-Authors: Ping Song, Ling-cang Cai, Tian-jiong Tao, Shuai Yuan, Hong Chen, Jin Huang, Xin-wen Zhao, Xue-jun WangAbstract:It is very important to determine the phase boundaries for materials with complex crystalline phase structures to construct their corresponding multi-phase equation of state. By measuring the sound velocity of Sn with different porosities, different shock-induced Melting Pressures along the solid-liquid phase boundary could be obtained. The incipient shock-induced Melting of porous Sn samples with two different porosities occurred at a Pressure of about 49.1 GPa for a porosity of 1.01 and 45.6 GPa for a porosity of 1.02, based on measurements of the sound velocity. The incipient shock-induced Melting Pressure of solid Sn was revised to 58.1 GPa using supplemental measurements of the sound velocity. Trivially, pores in Sn decreased the shock-induced Melting Pressure. Based on the measured longitudinal sound velocity data, a refined solid phase transition and the Hugoniot temperature-Pressure curve's trend are discussed. No bcc phase transition occurs along the Hugoniot for porous Sn; further investigation ...
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Sound velocity, temperature, Melting along the Hugoniot and equation of state for two porosity aluminums
Journal of Applied Physics, 2011Co-Authors: Ping Song, Ling-cang Cai, Shuai Yuan, Qing-song Wang, Xianming Zhou, Yi Zhang, Ji-dong WengAbstract:The shock-induced Melting of porous aluminum samples of two different porosities occurred at Pressures about 116 GPa and 81 GPa based on measurements of the sound velocity and shock temperature. An equation of state for porous aluminum was developed from these results, and the anharmonic parameters were determined quantitatively. The variation in the shock Melting Pressure, Melting temperature, and anharmonic parameter with porosity are explored.
Hiroshi Kambara - One of the best experts on this subject based on the ideXlab platform.
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Specific heat due to amorphous surface layers in liquid and solid 3He
Physica B-condensed Matter, 2000Co-Authors: Hiroshi Kambara, S. Kishishita, Takayoshi MamiyaAbstract:Abstract We have observed an excess specific heat for solid 3 He in silver sinter from Melting Pressure to 55 bar below a few tens of mK. The excess specific heat is nearly independent of temperature. Except for the solid near the Melting Pressure, the magnitude of the excess specific heat is almost constant throughout a wide Pressure region. This fact is explained in terms of the presence of about two layers of amorphous surface solid 3 He on the heterogeneous silver-sinter substrate.
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Specific heat due to amorphous surface in solid 3He
Europhysics Letters (EPL), 1999Co-Authors: Hiroshi Kambara, S. Kishishita, Taku Matsushita, Takayoshi MamiyaAbstract:We have observed an excess specific heat in bcc solid 3He at low temperatures and at Pressures between the Melting Pressure and 46 bar. The excess specific heat is nearly independent of temperature. In the solid just above the Melting Pressure, the magnitude of the anomaly is about 2.5 times larger than that at high Pressures. Except for the solid near the Melting Pressure, the magnitude is constant with Pressure and is nearly the same as that in liquid 3He in Vycor. This anomaly of the specific heat in solid 3He is explained in terms of the amorphous surface solid on a disordered substrate.
Js Xia - One of the best experts on this subject based on the ideXlab platform.
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Temperature dependence of the molar volumes of liquid and solid {sup 3}He at Melting Pressure near T{sub N}
Bulletin of the American Physical Society, 1995Co-Authors: Js Xia, E D AdamsAbstract:For temperatures above the solid ordering temperature T{sub N} = 0.934 mK, the molar volumes v{sub l} and v{sub s} of liquid and solid {sup 3}He at Melting Pressure, P{sub m} are determined primarily by the Melting Pressure and the compressibility. However, in the vicinity of T{sub N} and below, v{sub s}(T) is influenced greatly by the expansion coefficient, which becomes large and negative. Using existing thermodynamic data, the authors find that v{sub s}(T) has a minimum at T{sub N} with a negative slope for T < T{sub N}. A constant-volume, all-solid sample starting at T=0 with the Pressure just above P{sub m} would begin to melt as T{sub N} is approached, becoming all-solid again somewhat above T{sub N}.
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{sup 3}He Melting Pressure temperature scale below 25 mK
Bulletin of the American Physical Society, 1995Co-Authors: E D Adams, Js XiaAbstract:Using {sup 60}Co {gamma} ray anisotropy radiation as a primary thermometer, with a Pt NMR susceptibility secondary thermometer, the authors have made high precision measurements of the {sup 3}He Melting Pressure versus temperature from 500 {mu}K to 25 mK. Temperatures obtained for the fixed points on the Melting curve are: the superfluid A transition T{sub A} = 2.505 mK, the A-B transition T{sub AB} = 1.948 mK, and the solid ordering temperature T{sub N} = 0.934 mK. The authors provide a functional form for P(T), which, with the fixed points, constitutes a convenient temperature scale, based on a primary thermometer, usable to well below 1 mK.
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Melting Pressure of solid 3He through the magnetic-ordering transitions.
Physical review letters, 1993Co-Authors: Js Xia, E D AdamsAbstract:Magnetic ordering in solid 3 He has been studied by measuring the Melting Pressure through the various phase transitions. We find a discontinuity in entropy at the high-field-paramagnetic phase transition at low fields, indicating that it is first order. The entropy discontinuity decreases as the field increases and the transition broadens, becoming second order above a field of about 0.65 T. The first precise determination of the first-order phase boundaries has been made, from which thermodynamic data not previously available are obtained
