| 1. |
- Jacobsson, Per, et al.
(författare)
-
Thermal diffusivity of zinc as a function of pressure and temperature
- 1985
-
Ingår i: High Temperatures - High Pressures Vol. 17. - London : Pion Press. - 0 85086 124 1 ; , s. 103-109
-
Konferensbidrag (refereegranskat)abstract
- The thermal diffusivity and the electric resistivity of polycrystalline zinc have been measured as functions of temperature between 90 and 480 K at atmospheric pressure, and as functions of pressure up to 2 GPa (20 kbar) at room temperature. The pressure and temperature dependence of the thermal conductivity has been calculated by using literature data for the specific heat capacity. No minimum was found in the thermal conductivity at low temperatures. The pressure coefficient of the thermal conductivity was found to be 4.1 x 10-2 /GPa, which indicates that the Lorenz function of zinc decreases with increasing pressure.
|
|
| 2. |
- Lundberg, Bo, et al.
(författare)
-
Pressure-dependent electrical conductivity of polypyrrole
- 1985
-
Ingår i: Molecular Crystals and Liquid Crystals vol. 118. - : Informa UK Limited. - 0026-8941. ; , s. 155-158
-
Konferensbidrag (refereegranskat)abstract
- The results of pressure dependent electrical conductivity measurements in polypyrrole are consistent with a simple extension of the variable-range-hopping model of electronic transport in disordered media.
|
|
| 3. |
- Sundqvist, Bertil, et al.
(författare)
-
Pressure dependence of the electron-phonon interaction and Fermi-surface properties of Al, Au, bcc Li, Pb, and Pd
- 1985
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 32:4, s. 2200-2212
-
Tidskriftsartikel (refereegranskat)abstract
- The electrical resistance of Li, Pd, Au, and Pb is measured as a function of temperature and pressure in the region -20 °C to +30 °C and 0–1.3 GPa. Self-consistent linear muffin-tin orbital band-structure calculations of these elements and of Al are performed at normal and reduced volumes. Results are obtained for the density of states N(EF), the average Fermi ve- locity, the optical mass, the plasma frequency ω, and the volume dependence of these parameters. The pressure dependence of the electron-phonon interaction λ(p) is obtained from these measurements and the calculated ω(p). For the superconducting elements there is good agreement with the measured superconducting Tc(p). Results from our previous measurements and calculations on Al, V, Nb, and La and published results for ω(p) are included in this comparison. λ(p) increases with pressure for bcc Li and decreases for Pd and Au. Pressure is expected to suppress spin fluctuations much faster than λ(p) in Pd. The possibility of inducing superconductivity by pressure in Pd and bcc Li is discussed. The electronic Grüneisen parameter γe is obtained from λ(p) and the volume dependence of N(EF). Comparison with other results for γe generally shows good agreement.
|
|
| 4. |
- Sundqvist, Bertil
(författare)
-
Simple electronic resistance bridge with µOhm resolution at low current
- 1985
-
Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 56:11, s. 2166-2167
-
Tidskriftsartikel (refereegranskat)abstract
- A simple electronic resistance bridge is described. The bridge compares an unknown four-terminal resistor in the mOmega range with a precision resistance decade in the kOmega range. A lock-in amplifier is used as zero detector. With 10-mA exciting current a resolution better than one part in 3000 is obtained for unknown resistors in the range 3–100 mOmega. Experimental results are shown for a gold sample under pressure in the range 0–35° C and 0–1.3 GPa.
|
|
