Thermal conductivity measurement under hydrostatic pressure using the 3ω method

Abstract

We have designed and modeled new techniques, based on the 3 method, to measure thermal conductivity of liquids ͑ l ͒ and solids ͑ s ͒ under hydrostatic pressure ͑P͒. The system involves a solid sample immersed in a liquid pressure medium, both of which have unknown thermal properties. The temperature ͑T͒ and P dependance of l are first determined through the use of a modified 3 technique. This method uses a conducting wire (Pt, in this work), which is immersed in the pressure medium, as the heater/sensor. In addition to l , this allows for the accurate determination of the specific heat per volume of the liquid and Pt, ͑C͒ l and ͑C͒ Pt , respectively. The information of l and ͑C͒ l can then be used to make corrections to measurements of s , in which the sample is immersed in the pressure medium, and a metal strip acts as the heater/sensor. We present the T and P dependence of l and ͑C͒ l for the widely used pressure medium 3M Fluorinert FC77 up to 0.8 GPa. The measurement of s for a thermoelectric clathrate material, Sr 8 Ga 16 Ge 30 , in FC77 is analyzed in detail, and the refined data achieves an accuracy of 1%. The setup can be modified to measure and C up to 3.5 GPa.

Improved 3-omega measurement of thermal conductivity in liquid, gases, and powders using a metal-coated optical fiber

“…3,7,9,26 Metal-coated 3ω improves THW and solid-wire 3ω's heater by using a micron-scale metal-coated optical fiber rather than a thin solid metal wire. The thinner metal-cross-section results in signal improvements due to increased axial electrical and thermal resistance.…”

“…[1][2][3][4][5][6][7][8][9][10] Enhanced thermal property information will aid a diverse range of applications, including improved microprocessor heat removal, 11,12 higher efficiency thermoelectric materials, 13,14 and more effective minimally invasive cryosurgery. 15 The 3ω method and time domain thermo-reflectance (TDTR) are the dominant tools for measuring thermal conductivity in solids, while fluid samples have typically been studied with transient hot-wire (THW).…”

Application of the Three-Omega Method to Measurement of Thermal Conductivity and Thermal Diffusivity of Hydrogen Gas

“…Also, Moon and Jeong [7] and Birge [8] used the 3ω voltage to measure the heat capacities of liquids near the glass-transition temperature. Lee [9] measured the thermal conductivity of air with the three-omega method based on the solution of Chen et al [10] which includes wire properties.Studies related to application of the three-omega method to measurement of gas-phase properties are very scarce in the literature. The authors of this present article are preparing for measurement of the thermal conductivity and thermal diffusivity of hydrogen gas over a wide range of temperature and pressure [11] by the transient short-hot-wire method [12].…”

Nanofluids for Heat Transfer

“…The adaptation of the method for liquids is relatively recent (Chen et al, 2004;Heyd et al, 2008;Oh et al, 2008;S. R. Choi & Kim, 2008) but its use is increasingly common (Paul et al, 2010) in a variety of applications ranging from anemometry (Heyd et al, 2010) to thermal microscopy (Chirtoc & Henry, 2008).…”