Search results for " inelastic neutron scattering"

showing 3 items of 3 documents

Reply to “Comment to ‘Dynamics of supercooled confined water measured by deep inelastic neutron scattering’ by Y. Finkelstein and R. Moreh”

2019

We reply to the comment [Front. Phys. 14(5), 53605 (2019)] by Y. Finkelstein and R. Moreh on our article Front. Phys. 13(1), 138205 (2018). We agree with some of their criticisms about our calculation of the temperature effect on the kinetic energy of hydrogen atoms of supercooled confined water; we also agree with their statement that, in view of the current sensitivity of the technique, possible effects of the liquid-liquid water transition are hardly detected with deep inelastic neutron scattering (DINS). However, we disagree with their use of the translational mass ratio of a single water molecule and, in general, with their underestimation of collective effects.

Physicsliquid-liquid transitionPhysics and Astronomy (miscellaneous)HydrogenSettore FIS/07Front (oceanography)chemistry.chemical_elementvibrational density of statesMass ratioproton kinetic energyKinetic energy01 natural sciencesInelastic neutron scatteringSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)chemistry0103 physical sciencesLibrationlibrationAtomic physics010306 general physicsSupercoolingConfined waterdeep inelastic neutron scatteringsupercooled water
researchProduct

The boson peak of deeply cooled confined water reveals the existence of a low-temperature liquid-liquid crossover.

2014

International audience; The Boson peak of deeply cooled water confined in the pores of a silica xerogel is studied by inelastic neutron scattering at different hydration levels to separate the contributions from matrix, water on the pore surfaces and "internal" water. Our results reveal that at high hydration level, where the contribution from internal water is dominant, the temperature dependence of the Boson peak intensity shows an inflection point at about 225 K. The complementary use of differential scanning calorimetry to describe the thermodynamics of the system allows identifying the inflection point as the signature of a water liquid-liquid crossover.

liquid-liquid transition[SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry Molecular Biology/Structural Biology [q-bio.BM]CrossovereducationGeneral Physics and Astronomyinelastic neutron scatteringInelastic neutron scatteringSettore FIS/03 - Fisica Della MateriaMatrix (geology)Differential scanning calorimetryPhysical and Theoretical ChemistryPhysics::Atmospheric and Oceanic PhysicsCondensed matter physicsCalorimetry Differential Scanning[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry Molecular Biology/Structural Biology [q-bio.BM]ChemistrySolvationwater anomalieWaterSilicon DioxideSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Cold Temperaturewater anomalies; differential scanning calorimetry; inelastic neutron scattering; liquid-liquid transitionInflection pointChemical physicsThermodynamicsBoson peakdifferential scanning calorimetryGelsPorosityIntensity (heat transfer)
researchProduct

Supercooled Water Confined in a Silica Xerogel: Temperature and Pressure Dependence of Boson Peak and of Mean Square Displacements

2013

A silica xerogel can be obtained from an alcoxide precursor (TMOS, tetramethylortosilcate) via the sol-gel method: TMOS hydrolysis and subsequent polycondensation yields a solid, disordered, porous SiO2 matrix (average pore dimensions ~20Å). Inside the pores water is trapped and the hydration level h=gr[H2O]/gr[SiO2] can be easily controlled. The presence and temperature dependence of the boson peak (BP) in xerogel confined supercooled water was studied with inelastic neutron scattering (spectrometer IN6 at ILL, Grenoble) in xerogel samples having h=0.4 and h=0.2. After careful subtraction of the contributions arising from the matrix and from quasi-elastic scattering, the BP contribution wa…

silica xerogel boson peak inelastic neutron scattering excess density of states LDL->HDL transition mean square displacements elastic neutron scattering protein dynamical transitionSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
researchProduct