Heat capacity and thermal conductivity from pulsed wire probe measurements under pressure

• If a metal wire immersed in an electrically insulating medium is heated by a known constant power, the thermal conductivity of the medium may be deduced from the temperature variation of the wire. In this work it is shown that further analysis of this variation also permits the specific heat capacity or the thermal diffusivity to be determined. A nickel wire is used both as a heater and as a temperature sensor. The power is kept constant by electronic means, and the resistance measured by a four probe technique. Eight temperature values are recorded during the power pulse, which has a typical duration of 1 s. Data acquisition and calculation of thermal conductivity and specific heat capacity are carried out automatically using a desk calculator. This extended method has been tested by studying glycerol in its amorphous and crystalline states in the range 130-300 K and at pressures of up to 0.8 GPa.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

Heat capacity

specific heat

thermal conductivity

thermal diffusivity

pulse method

dynamic method

hot-wire method

high pressure

glycerol

Publikations- och innehållstyp

ref (ämneskategori)

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