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Experiments on Liquid – Gas Phase Transition. Huanlong Liu. Liquid – Gas Phase Transition. O(1) Universality Class – 3d Ising. Lattice – gas interpretation: Transformation:. intermolecular potential. is the number of nearest neighbors. Critical component.
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Experiments on Liquid – Gas Phase Transition Huanlong Liu Phase Transition (G85.2017) Fall 2010
Liquid – Gas Phase Transition Phase Transition (G85.2017) Fall 2010
O(1) Universality Class – 3d Ising • Lattice – gas interpretation: • Transformation: intermolecular potential is the number of nearest neighbors Phase Transition (G85.2017) Fall 2010
Critical component • Density difference(order parameter): • Isothermal compressibility: • Specific heat: • Correlation length: Phase Transition (G85.2017) Fall 2010
Outline • Thermal Dynamic property measurements • Difficulties • Coexistence curve • Specific heat • Susceptibility(isothermal compressibility) • Correlation length Phase Transition (G85.2017) Fall 2010
Difficulties • Small asymptotic region: • As Therefore, gravity will dramatically change the density with respect of height Phase Transition (G85.2017) Fall 2010
Solutions • Reduce height – finite size effect – doesn’t work • Add correlation – to – scaling terms • Reduce gravity Phase Transition (G85.2017) Fall 2010
Another difficulty Phase Transition (G85.2017) Fall 2010
Coexistence Curve – I • Measurement: • Coexistence curve in critical region of HCFC-123, (1) HFC-32,(2) and HFC-125 (3) • Main Results: • Publications: • Okazaki et.al (1982) • Tanlkawa(1990) • Kuwabara(1995) Phase Transition (G85.2017) Fall 2010
Experiment setup Phase Transition (G85.2017) Fall 2010
Experiment setup old New – higher T Phase Transition (G85.2017) Fall 2010
Result: HCFC-123 Phase Transition (G85.2017) Fall 2010
Results: HFC-32 Phase Transition (G85.2017) Fall 2010
Results: HFC-25 Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II • Measurement: • Coexistence curve, isothermal compressibility and the density as a function of chemical potential of N2 and Ne • Main Result: • (perhaps best agreement up to date) • Publications: • M. W. Pestak and M. H. W. Chan, PRB 30 1 (1984) Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II • Measure four capacitances between five plates • Reduced density as a function of dielectric: • Able to tell the gravity – rounded region Phase Transition (G85.2017) Fall 2010
Experiment setup Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II Determine the gravity – rounded region Determine the first correction to scale term Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II One phase compressibility Two phase compressibility Phase Transition (G85.2017) Fall 2010
Coexistence Curve – II Phase Transition (G85.2017) Fall 2010
Order parameter and compressibility • The coexistence curve and critical amplitude ratios of CHF3 and Xenon • Narger et.al. PRB 39 13(1989), PRB 39 16(1989), PRB 42 10(1990) Phase Transition (G85.2017) Fall 2010
Experiment setup Prism cell Fringe Phase Transition (G85.2017) Fall 2010
Results – xenon Phase Transition (G85.2017) Fall 2010
Results – xenon Phase Transition (G85.2017) Fall 2010
Results – CHF3 Phase Transition (G85.2017) Fall 2010
Results – CHF3 Phase Transition (G85.2017) Fall 2010
Specific heat • Specific heat of SF6 • , asymptotic region: • A. Haupt and J. Straub Phys. Rev. E 29 2(1999) Phase Transition (G85.2017) Fall 2010
Experimental detail Phase Transition (G85.2017) Fall 2010
results μg condition Phase Transition (G85.2017) Fall 2010
Find asymptotic region Phase Transition (G85.2017) Fall 2010
Correlation length - II • Long range correlation length and isothermal compressibility of CO2 and Ni near critical point by light scattering • Lunacek et.al PRL 27 13(1971), Cannell PRA 12 1(1975) Phase Transition (G85.2017) Fall 2010
Experiment setup Phase Transition (G85.2017) Fall 2010
Compressibility Phase Transition (G85.2017) Fall 2010
Results – CO2 Phase Transition (G85.2017) Fall 2010
Results – SF6 Phase Transition (G85.2017) Fall 2010
Correlation length - II • Small angle neutron scattering from D2O in the critical region • D M Sullivan, G W Neilson, H E Fischer and A R Rennie J. Phys.: Condens. Matter 12(2000) Phase Transition (G85.2017) Fall 2010
Introduction • Ornstein – Zernike critical theory: • For pure one – component fluid: • Critical component: • Cannot determine Phase Transition (G85.2017) Fall 2010
Experimental Setup Phase Transition (G85.2017) Fall 2010
Results – fitting Phase Transition (G85.2017) Fall 2010
Compressibility Phase Transition (G85.2017) Fall 2010
Correlation length Phase Transition (G85.2017) Fall 2010
Correlation length - III • Universal critical – scattering function of CO2 • Damay et. al. PRB 58 18(1998) Phase Transition (G85.2017) Fall 2010
Experiments and Results Phase Transition (G85.2017) Fall 2010
Thank you! Phase Transition (G85.2017) Fall 2010