| 1. |
- Lundberg, Bo, et al.
(författare)
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Basal plane resistivity and phase diagram of HNO3 intercalated graphite in the range 130–320 K and 0–1.6 GPa
- 1986
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Ingår i: Solid State Communications. - : Elsevier Science Ltd.. - 0038-1098 .- 1879-2766. ; 58:10, s. 747-751
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Tidskriftsartikel (refereegranskat)abstract
- The basal plane resistivity varrho of stages 3–5 HNO3 intercalated graphite has been measured as a function of temperature T and pressure p in the range 130–320 K and 0–1.6 GPa (16 kbar). A contactless method was used. The phase boundary of the 250 K ordering transition at zero pressure was traced up to 320 K through the corresponding anomaly in varrho. The pressure dependence of varrho was strongly stage dependent, such that for stages 3, 4 and 5 the observed pressure coefficients (1/varrho)dvarrho/dp were approximately 0.08, −0.08, and −0.22 GPa−1, respectively, near zero pressure.
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| 2. |
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| 3. |
- Lundberg, Bo, et al.
(författare)
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Pressure-dependent electrical conductivity of polypyrrole
- 1985
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Ingår i: Molecular Crystals and Liquid Crystals vol. 118. - : Informa UK Limited. - 0026-8941. ; , s. 155-158
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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.
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| 4. |
- Lundberg, Bo, et al.
(författare)
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Pressure effects on electrical conductivities in intercalated graphite and doped polypyrrole
- 1984
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Ingår i: Journal de Physique Colloque vol. 45. - : EDP Sciences. - 0449-1947. ; , s. 213-216
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Konferensbidrag (refereegranskat)abstract
- We have measured the pressure dependence up to 2.5 GPa of the electrical resistance of the acceptor intercalated graphites CnFeCl3, CnSbF5, and CnHNO3. The slope of resistance versus pressure is approximately the same in all cases. Two different types of high pressure transitions are observed in CnSbF5 and CnHNO3. The results of electrical resistance measurements under pressure in polypyrrole are consistent with a simple extension of the variable-range-hopping model. We infer for this material that the density of states at the Fermi level increases with pressure.
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| 5. |
- Lundberg, Bo, et al.
(författare)
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Resistivity of a composite conducting polymer as a function of temperature, pressure, and environment: Applications as a pressure and gas concentration transducer
- 1986
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 60:3, s. 1074-1079
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Tidskriftsartikel (refereegranskat)abstract
- The resistivity of a commercial carbon-filled composite conducting polymer (ET-Semicon[large-closed-square]) has been measured as a function of temperature between 80 and 400 K and under pressure up to 1.5 GPa (15 kbar). Large changes in resistivity were observed. The resistivity was also very sensitive to the presence of certain solvents and hydrocarbons. The results are explained as percolation effects caused by changes in volume due to pressure, thermal expansion, or dissolved solvents. The material studied is found to have a wide range of potential applications for pressure measurements and as a transducer for gas or liquid concentration.
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| 6. |
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| 7. |
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| 8. |
- Sundqvist, Bertil, et al.
(författare)
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Contactless basal plane resistivity measurements under pressure and the pressure/temperature phase diagram of stage 2 SbCl5 intercalated graphite
- 1986
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Ingår i: Journal of Physics C: Solid State Physics. - Bristol : Institute of Physics. - 0022-3719. ; 19:35, s. 6915-6929
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Tidskriftsartikel (refereegranskat)abstract
- The basal plane resistivity rho of stage 2 SbCl5 intercalated graphite has been measured as a function of temperature T and pressure p in the range 195-300K and 0-1.75 GPa, using a contactless method. rho is found to increase with increasing p. New evidence is found for the existence of the high-pressure (>1 GPa) phase suggested by Houser and co-workers (1984). The p/T phase boundaries for the low T(<230K) and intermediate p (>0.35 GPa) ordered phases are outlined. A re-analysis of previous results for stage 1 SbF5 intercalated graphite indicates a similar phase diagram for this material.
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| 9. |
- Sundqvist, Bertil, et al.
(författare)
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Contactless measurements of the basal plane resistivity of FeCl3 and SbF5 intercalated graphites under pressure
- 1984
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Ingår i: Journal of Physics C: Solid State Physics. - : IOP Publishing. - 0368-3516 .- 0022-3719. ; 17:5, s. L133-L138
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Tidskriftsartikel (refereegranskat)abstract
- The basal plane resistivities of stage 1 SbF5 and stage 2 FeCl3 graphite intercalation compounds have been measured for the first time at high pressure, using a recently developed contactless method. The resistivity is found to increase with increasing pressure in both materials. In the SbF5 intercalated material a phase transition was found at 1.2 GPa. This could be the first pressure-induced stage transformation observed in an acceptor intercalation compound.
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| 10. |
- Sundqvist, Bertil, et al.
(författare)
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Contactless methods for measuring electrical resistivity under pressure
- 1984
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Ingår i: High Pressure in Science and Technology, Part III: General Topics. - New York : North-Holland, Elsevier Science Publishing Co., Inc.. - 0444009310 - 0444009329 ; , s. 281-284
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Konferensbidrag (refereegranskat)abstract
- A new inductive contactless method to measure the electrical conductivity of metals under pressure is described. A ferromagnetic Metglas 2826 toroid core is used to minimize errors due to external magnetic fields. Experimental results for tin and brass are shown to agree very well with conventional four-terminal measurements.
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