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Thermal conductivit...
Thermal conductivity and electrical resistivity of gadolinium as functions of pressure and temperatur
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- Jacobsson, Per (författare)
- Umeå universitet,Institutionen för fysik
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- Sundqvist, Bertil (författare)
- Umeå universitet,Institutionen för fysik
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(creator_code:org_t)
- 1989
- 1989
- Engelska.
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 40:14, s. 9541-9551
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http://link.aps.org/...
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visa fler...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The electrical resistivity ρ and the thermal diffusivity a of gadolinium have been measured as functions of T in the range 45–400 K. The thermal conductivity λ has been calculated from a and experimental data for the specific-heat capacity, cp. λ can be analyzed in terms of simple models for the lattice and electronic components above the Curie temperature TC≃291.4 K. Below TC an additional term, identified as a magnon (spin-wave) thermal conductivity λm, is found. ρ and λ have also been studied as functions of T and P in the range 150–400 K and 0–2.5 GPa. The Lorenz function L=ρλ/T increases by about 20%/GPa under pressure due to a very strong pressure dependence of the lattice thermal conductivity. The pressure coefficients of ρ and λ are -5.1×10-2 and 0.22 GPa-1, respectively, at 300 K (above TC), and 0 and 0.16 GPa-1 at 200 K (below TC). TC and the spin-reorganization temperature Tr≃219 K both decrease under pressure, at the rates -14.0 and -22.0 K/GPa, respectively. Although the magnitude of λm cannot be accurately calculated from the zero-pressure data for λ, the temperature dependence of dλ/dP allows us to distinguish between several models and assign a value of λm≃1.5 W m-1 K-1, or 16.0% of λ, at 200 K.
Ämnesord
- NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Condensed Matter Physics (hsv//eng)
Nyckelord
- Thermal conductivity
- thermal diffusivity
- specific heat capacity
- electrical resistivity
- conductivity
- Lorenz function
- high pressure
- spin scattering
- spin wave transport
- magnons
- Curie temperature
- phonon thermal conductivity
- lattice thermal conductivity
- Condensed matter physics
- Kondenserade materiens fysik
- fysik
- Physics
Publikations- och innehållstyp
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- art (ämneskategori)
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