Size-Dependent Transport-Coefficient Effects in Fermi Liquids

AbstractDetecting hydrodynamic fingerprints in the flow of electrons in solids constitutes a dynamic field of investigation in contemporary condensed matter physics. Most attention has been focused on the regime near the degeneracy temperature when the thermal velocity can present a spatially modulated profile. Here, we report on the observation of a hydrodynamic feature in the flow of quasi-ballistic degenerate electrons in bulk antimony. By scrutinizing the temperature dependence of thermal and electric resistivities, we detect a size-dependent departure from the Wiedemann-Franz law, unexpected in the momentum-relaxing picture of transport. This observation finds a natural explanation in the hydrodynamic picture, where upon warming, momentum-conserving collisions reduce quadratically in temperature both viscosity and thermal diffusivity. This effect has been established theoretically and experimentally in normal-state liquid 3He. The comparison of electrons in antimony and fermions in 3He paves the way to a quantification of momentum-conserving fermion-fermion collision rate in different Fermi liquids.

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THE TIME DEPENDENT TRANSPORT COEFFICIENT FOR THE TWO-COMPONENT PLASMA

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19797254 ◽

1979 ◽

Vol 40 (C7) ◽

pp. C7-525-C7-526

Author(s):

W. Rozmus

Keyword(s):

Transport Coefficient ◽

Time Dependent ◽

Two Component ◽

Component Plasma ◽

Dependent Transport

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Grain Size Dependent Transport and Magnetoresistance Behavior of Chemical Solution Deposition Grown Nanostructured La07Sr03MnO3 Manganite Films

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.an51 ◽

2008 ◽

Vol 8 (8) ◽

pp. 4146-4151 ◽

Cited By ~ 21

Author(s):

R. N. Parmar ◽

J. H. Markna ◽

P. S. Solanki ◽

R. R. Doshi ◽

P. S. Vachhani ◽

...

Keyword(s):

Thin Films ◽

Grain Size ◽

Chemical Solution Deposition ◽

Chemical Solution ◽

Time Intervals ◽

Solution Deposition ◽

Size Dependent ◽

Time Control ◽

Insulator Metal Transition ◽

Dependent Transport

Grain-size dependence of electronic transport and magnetoresistance (MR) properties of nanostructured La0.7Sr0.3 MnO3 (LSMO) manganite thin films on LaAlO3 (100) single crystal substrates prepared using Chemical Solution Deposition (CSD) technique have been studied. The LSMO thin films were annealed at temperatures in the range of 700–1000 °C for different time intervals [6 h and 12 h] and crystallized as singlephase LSMO. Microstructural studies carried out using AFM show a marginal increase in the grain-size from 50 to 90 nm as the temperature was varied from 700 °C to 1000 °C respectively. It has been observed that the insulator-metal transition (TP) and MR depend on the grain size. In zero applied field, resistivity reduction is ∼ 103 at 5 K for the films annealed at 700 °C [TP ∼ 341 K] and 1000 °C [TP ∼ 373 K]. MR versus H isotherms reveal that MR enhances in the vicinity of TP but decreases at low temperatures. The results obtained from the electronic and magnetotransport studies are in good agreement with the change in surface morphology of the films studied, which shows that the randomly distributed domains are composed of faceted grains. Synthesizing conditions, annealing temperature and time control the growth and alignment of grains into the domains, which cause better conduction at grain interface.

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