Photothermal methods for determination of thermal properties of bulk materials and thin films

Open Physics ◽  
2010 ◽  
Vol 8 (2) ◽  
Author(s):  
Jerzy Bodzenta ◽  
Anna Kaźmierczak-Bałata ◽  
Jacek Mazur
Keyword(s):  
Thin Films ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Heat Transport ◽  
Temperature Fields ◽  
Nonstationary Temperature ◽  
Measuring Techniques ◽  
Heat Transport Properties ◽  
Photothermal Methods

AbstractInformation on the thermal properties of materials is very important both in fundamental physical research and in engineering applications. The development of materials with desirable heat transport properties requires methods for their experimental determination. In this paper basic concepts of the measurement of parameters describing the heat transport in solids are discussed. Attention is paid to methods utilizing nonstationary temperature fields, especially to photothermal methods in which the temperature disturbance in the investigated sample is generated through light absorption. Exemplary photothermal measuring techniques, which can be realized using common experimental equipment, are described in detail. It is shown that using these techniques it is possible to determine the thermal diffusivity of bulk transparent samples, opaque and semi-transparent plate-form samples, and the thermal conductivity of thin films deposited on thick substrates. Results of the investigation of thermal diffusivity of the ground in the polar region, which is based on the analysis of the propagation of the thermal wave generated by sun-light, are also presented. Based on chosen examples one can state that photothermal techniques can be used for determination of the thermal properties of very different materials.

Thermal Properties of Thin Metallic Layer Deposited on Insulators: Effect of the Interface on the Independent Determination of the Thermal Diffusivity and Conductivity of the Layer

2008 ◽  
Author(s):  
Danie`le Fournier ◽  
Jean Paul Roger ◽  
Christian Fretigny
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Thermal Resistance ◽  
Thermal Contact ◽  
Heat Diffusion ◽  
Metallic Layer ◽  
Good Thermal Contact ◽  
Lateral Heat

Lateral heat diffusion thermoreflectance is a very powerful tool for determining directly the thermal diffusivity of layered structures. To do that, experimental data are fitted with the help of a heat diffusion model in which the ratio between the thermal conductivity k and the thermal diffusivity D of each layer is fixed, and the thermal properties of the substrate are known. We have shown in a previous work that it is possible to determine independently the thermal diffusivity and the thermal conductivity of a metallic layer deposited on an insulator, by taking into consideration all the data obtained at different modulation frequencies. Moreover, it is well known that to prevent a lack of adhesion of a gold film deposited on substrates like silica, an intermediate very thin (Cr or Ti) layer is deposited to assure a good thermal contact. We extend our previous work: the asymptotic behaviour determination of the surface temperature wave at large distances from the modulated point heat source for one layer deposited on the substrate to the two layers model. In this case (very thin adhesion coating whose thermal properties and thickness are known), it can be establish that the thermal diffusivity and the thermal conductivity of the top layer can still be determined independently. It is interesting to underline that the calculus can also be extended to the case of a thermal contact resistance which has often to be taken into account between two solids. We call thermal resistance a very thin layer exhibiting a very low thermal conductivity. In this case, the three parameters we have to determine are the thermal conductivity and the thermal diffusivity of the layer and the thermal resistance. We will show that, in this case, the thermal conductivity of the layer is always obtained independently of a bound of the couple thermal resistance – thermal diffusivity, the thermal diffusivity being under bounded and the thermal resistance lower bounded. Experimental results on thin gold layers deposited on silica with and without adhesion layers are presented to illustrate the method. Discussions on the accuracy will also be presented.

Anomaly of Thermal Properties in Thin Films of La1-x SrxCoO3 Series Fabricated as Thermoelectric Materials

2002 ◽  
Vol 730 ◽  
Author(s):  
Yoshiaki Takata ◽  
Hajime Haneda ◽  
Yutaka Adachi ◽  
Yoshiki Wada ◽  
Takefumi Mitsuhashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Thermoelectric Materials ◽  
Signal Analysis ◽  
Material Synthesis ◽  
Thermo Electric ◽  
Optical Pump ◽  
Pump And Probe ◽  
Reflection Geometry

AbstractComposition spreads of La1-xSrxCoO3 (LSCO) were synthesized as thermo-electric transducer material by means of combinatorial material synthesis, and information on their thermal diffusivity throughout the specimens was obtained. Meanwhile, it is anticipated that the composition spreads of LSCO have a variety of characteristic properties of light absorption corresponding to their composition, namely their compositional variable, x. Hence, we used transient optical pump-and-probe techniques in a reflection geometry to measure thermal diffusion times on LSCO. The results of signal analysis indicate that LSCO is a peculiar synthesized substance whose apparent thermal diffusivity, 1/ι, changes abruptly at the critical point, where the compositional variable x is equal to 0.3.

The insensitivity of thermal diffusivity of natural sediments to saturation

2018 ◽  
Vol 58 (2) ◽  
pp. 705
Author(s):  
Ayman Ezdini ◽  
James Griffith ◽  
Nick Lange ◽  
Soroush Tehrani ◽  
Hamad Roshan ◽  
...  
Keyword(s):  
Grain Size ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Clay Content ◽  
Heat Diffusion ◽  
Reservoir Properties ◽  
Needle Probe ◽  
Close Relationship ◽  
Porosity And Permeability

This extended abstract presents a ground-breaking study of thermal properties of soils and their dependency on saturation. The paper tries to prove that thermal diffusivity is not significantly dependent on saturation due to its close relationship with saturation-independent parameters such as thermal conductivity and volumetric heat capacity. The investigation is divided into two main scopes of work: the first is to build statistical analysis using the Monte Carlo technique by means of random sampling certain soil thermal properties; and the second is to experimentally validate the statistical models. The experimental framework of the study encompasses the measurement of thermal properties of different soil samples. These samples varied in terms of grain size, percentage clay content, and level of saturation. The experiments were carried out using a KD2-Pro Dual Needle Probe Thermal Properties Analyser. The results demonstrate that saturation has a negligible effect on thermal diffusivity of soils but an inverse relationship exists between diffusivity and clay content. Furthermore, the variation in grain size effect on diffusivity is within 5%. The study shows a correlation between lithology, porosity, and thermal properties. The implications are numerous: from the determination of unwanted heat diffusion of pipelines to the estimation of reservoir properties such as porosity and permeability.

The Simultaneous Measurement of Thermal Conductivity, Thermal Diffusivity, and Perfusion in Small Volumes of Tissue

1984 ◽  
Vol 106 (3) ◽  
pp. 192-197 ◽  
Author(s):  
J. W. Valvano ◽  
J. T. Allen ◽  
H. F. Bowman
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Tissue Perfusion ◽  
Effective Thermal Diffusivity ◽  
Liver Preparation ◽  
Improved Technique ◽  
Power Response

An improved technique is presented for the “in-vivo” determination of thermal conductivity, thermal diffusivity, and perfusion using a self-heated spherical thermistor probe. In the presence of flow, solution of the time-dependent, probe-tissue coupled thermal model allows the measurement of “effective” thermal conductivity and “effective” thermal diffusivity, which represent the thermal properties of the perfused tissue. Perfusion can be quantified from both “effective” thermal properties. In the presence of flow, it has been shown that the transient power response does not follow t−1/2 as has been previously assumed. An isolated rat liver preparation has been developed to validate the measurement technique. Radioactive microspheres are used to determine the true perfusion from the total collected hepatic vein flow. Experimental data demonstrates the ability to quantify perfusion in small volumes of tissue.

Anomaly of Thermal Properties in Thin Films of La1-xSrxCoO3 Series Synthesized with a Combinatorial Processing

2001 ◽  
Vol 700 ◽  
Author(s):  
Yoshiaki Takata ◽  
Yutaka Adachi ◽  
Hajime Haneda ◽  
Yoshiki Wada ◽  
Makoto Ohtani ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
High Precision ◽  
Distribution Profile ◽  
Excitation Light ◽  
X Ray ◽  
Fundamental Wavelength ◽  
Thermal Diffusivities ◽  
Grating Spacing

AbstractThe thermal diffusivities throughout a composition-spread film comprising La1- xSrxCoO3 series were determined by Transient Reflecting Grating (TRG) measurements. Thermal diffusivities of transparent SrCoO3 film and SrTiO3 substrate were determined by using third harmonics having wavelength of 266 nm as an excitation light with only a certain length of grating spacing. The thermal diffusivities of them were 0.02 and 0.05 cm2/s, respectively. With regard to untransparent thin films, the experiment was performed by setting three kinds of grating spacing for the excitation light having the fundamental wavelength, 800 nm in order to obtain high precision. The distribution profile of obtained values of the thermal diffusivity throughout the sample was traced as 0.06 - 0.18 - 0.01 cm2/s corresponding to the variation of in La1-xSrxCoO3, thus showing a convex profile, however, this anomalous profile was verified by comparing with the data obtained by the X-ray diffractometer.

Heat conduction in silicon thin films: Effect of microstructure

1995 ◽  
Vol 10 (8) ◽  
pp. 1889-1896 ◽  
Author(s):  
Lanhua Wei ◽  
Mark Vaudin ◽  
Cheol Song Hwang ◽  
Grady White ◽  
Jason Xu ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Chemical Vapor ◽  
Bulk Silicon ◽  
Amorphous Films ◽  
Silicon Thin Films ◽  
Diffusivity Measurements ◽  
Pressure Chemical ◽  
Wave Technique

A study was made of the thermal properties of low pressure chemical vapor deposition (LPCVD) silicon thin films with amorphous and polycrystalline microstructures, produced by varying the substrate temperature. Thermal diffusivity measurements were conducted using a thermal wave technique. The thermal diffusivity of the polycrystalline films was found to be about three times that of the amorphous films, but about one eighth that of bulk silicon single crystals. There was also an indication that the diffusivity increased with deposition temperature above the transition temperature from the amorphous to the polycrystalline state. The relationships between the thermal properties and microstructural features, such as grain size and grain boundary, are discussed.

Thermal Properties of CN Thin Films Measured by Photothermal Methods

2001 ◽  
Vol 8 (3-4) ◽  
pp. 233-239
Author(s):  
J. Bodzenta ◽  
B. Burak ◽  
J. Mazur ◽  
J. Szmidt
Keyword(s):  
Thin Films ◽  
Thermal Properties ◽  
Photothermal Methods

scholarly journals Determination of Some Mechanical and Thermal Properties of Cattle Manure Pellets

2017 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Javad Rezaeifar ◽  
Mansoureh Pourjafar
Keyword(s):  
Shear Stress ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Organic Materials ◽  
Cattle Manure ◽  
Natural State ◽  
Mechanical And Thermal Properties ◽  
Livestock Waste ◽  
Valuable Source

<p>One of the important subsidiary materials of livestock units is excreta. The livestock waste (including the combination of the Cattle Manure and products case in the bed) as a valuable source of the minerals (Nitrogen 1.78 % , phosphor us 0.5% and potassium 0.99%).For the transportation of the cattle manure in the natural state is difficult and costly due to being low the special mass and the nature of mass. It is produced around 6 million thons the cattle manure yearly in Iran which it is usually filled in the place according to the lack of organic materials of the soils country, the use of the cattle manure causes increasing the productivity of crops. We usually need to some of the mechanical and thermal properties of the cattle manure for producing the pellet by Extruder, so we Survey some of the mechanical and thermal properties of the cattle manure pellet in this research such as the shear stress and the coefficient of thermal diffusivity cattle manure. We obtain the coefficient of the thermal diffusivity manure (</p>

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