I guess thermal conductivity could be measured by (at least):

a) thermoreflectance methods (see Pr. Cahill papers for example).

It depends on the material you want to investigate. If you cannot build up your own system but it is tricky, or you can also buy from http://www.microsanj.com/

b) 3-omega

In case you can pattern a thin metal wire on your thin film, this wire will act as a heater and temperature sensor. You need vacuum, cooling system, lock in amplifier, a frequency sweep (mHz to MHz) then output the 3rd harmonic: this signal is proportional to the thermal conductivity.

Raman spectroscopy can be a powerful tool measuring thin film thermal conductivity. Another approach would be photothermal radiometry. Wish it helps.

Dear Yun Shen Zhou, could you explain how Raman spectroscopy can help in measuring the thermal conductivity?

Laser flash methods are now the standards for measuring the thermal conductivity

3-omega method is frequently used for such measurements.

I've also heard of the Raman technique. It works on the assumption that the laser is absorbed at the surface, and the substrate is very thermally conductive. The Raman signal is sensitive to (surface) temperature, and you assume the film/substrate interface temperature to be room temperature. That gives you an equilibrium temperature gradient across film thickness x, which gives you thermal conductivity. Check out papers and thesis of Etienne Drahi.

Yes. The photothermal radiometry method is also called laser flash method.

For the characterization using Raman spectroscopy, I recommend reading following articles:

Superior Thermal Conductivity of Single-Layer Graphene, Nano Lett., 2008, 8 (3), pp 902–907

Measurement of porous silicon thermal conductivity by micro-Raman scattering, J. Appl. Phys. 86, 4700 (1999)

Thermal conductivity of suspended pristine graphene measured by Raman spectroscopy, Phys. Rev. B 83, 081419(R) (2011)

Hopefully, it helps.

There is also an advanced system called Physical Property measurement System (PPMS) that can measure all physical properties of the samples simultaneously such as electrical and thermal conductivity, Seebeck coefficient and etc.

Although the typical laser flash method is excellent for measuring the thermal conductivity of the bulk materials, it is not accurate for measuring the thermal conductivity of the thin films.

Please define your system exactly (substrate material, thickness and roughness, material and thickness of thin film, preparation conditions or/and method, lateral diameters, homogeneity ...), otherwise it make no sense to discuss the measuring technique. If the sample have an electric conductivity you can use Wiedemann–Franz law. For the electrical measuring of sheet resistance you can use 4-point-probe (for example linear van der Pauw method).

Please read the review article of A. Balandin, Thermal properties of graphene and nanostructured carbon materials, Nature Materials, V. 10, 569, 2011. DOI: 10.1038/NMAT3064

There are several techniques to measure the thermal conductivity of the thin films. In which transient plane source (TPS) technique is a very good technique to measure the themal conductivtyof thin films

Recently I follow a Webinar of C-Therm about "Thermal Conductivity Characterization of Thermoelectric Materials". The C-Therm produce and distributed a device for this type of measurement, that is easy to use and non-destructive. The principle applied in measurements is that of "Modified transient plane source". For more informations you could contact the Managing Director Adam Harris .

The 3 Omega method is usually considered.

Take care of the material you get. If the material is an insulator or a conductor, you should consider the conduction AND, or not, the convection of the free electrons.

Thanks everybody for your valuable suggestions and information, it helps me a lot. we have 2 variety of films one is thicker (few micron) and another is thinner (100-300 nm on glass substrate) we used polymer material. It is easy to find the thermal conductivity and Seebeck co efficient, measuring thermal conductivity is difficult and thermal isolation of sample during measurement is required. Moreover modified Harman method cannot be used in measuring thin film ZT.

Dear Senthilumaran,

May I join the discussion lately.

I would contribute from the point of view of an engineer. The measuring concept is that the quantities are measured as they defined. Having a sheet of material with thickness d, area A and the conductivity K, then its thermal conductance Gth=kA/d.

The Gth= deltaT/ P, where, deltaT is temperature deference across the sheet passing in it a heat power P. Practically we push in the film a heat rate of flow P and measure the temperature difference deltaT. Proper arrangements of proper temperature sensors and constant heat flow sources can be thought to make the measurements.

One of such arrangements is to sandwich the sheet between two metallic wires.Since metals have good thermal conductivity, t here temperature will be constant. Then measuring the temperature of the wires, one gets delta T. Also, the heat flow is more or less confined in the wire and P can be also measured.

Thank you

Dear Abdelhalim Zekry, thanks for your idea and discussion.

Dear Mikko, thanks for reference it is comprehensive. A commercial Time Domain Reflectance is available from Linseis in Germany.

http://www.linseis.com/en/our-products/thermal-diffusivity-thermal-conductivity/tf-lfa-laserflash-for-thin-films/