https://www.researchgate.net/post/Measuring_density_of_thin_films-can_anyone_help

I think we can measure the approximate density by using the SEM micrographs..

Saqib & Masoud,

seriously, how would you measure density (kg/m^3) from SEM micrographs or EDX???

(Edit: the post proposing EDX has meanwhile disappeared.)

since density is mass per volume, that might give you an idea on what could be suitable. If your film thickness is homogeneous, measure it (e.g. by cross sectional SEM, by optical means) and weigh the film (weight after film formation minus weight of bare substrate). Of course this only works satisfactorily if your weight determination is sufficiently precise. It therefore depends on the specifics of your experiment.

For other suggestions check the link Werner has provided.

Use XRR , i believe its good technique to measure the density of thin film.

If your thin film is uniform and the substrate and film's surface area is measurable, you can easily use SEM to estimate the thickness of the layer. Then, it just need to measure the weight of your sample before and after deposition and subtract these two numbers. As I said, if the thickness of your film appears uniform, this way works. So you just need to divide the subtract number by the volume of the layer (which is surface are multiply by thickness of the layer)

May be you could try XRR for the density of films.

If you know the refractive index and density of bulk material and the refractive index of your thin film you can use effective medium approximation to calculate the volume fractions of air and bulk phases in your thin film - f(air) and f(bulk), respectively. Than using the relation ro(film) = ro(air) x f(air)+ro(bulk) x f(bulk) you can calculate the density (ro(film)) of your thin film.( ro (bulk) is the density of bulk material; ro (air) =1 is the density of air; 'x' denotes product)

there are different ways to get an estimation of the density. I believe one easy way to get a relative precise result is to measure the weight and volume (using principle of Archimedes to measure volume) of the substrate with and without the film,

Measuring the weight of the substrate prior and after deposition of thin film for determination of film density may work only in the particular case of very thick films (hundreds of microns). Otherwise the measuring precision is not enough. If you know the approximate thickness and density of films along with the size of the substrate you can calculate the approximate weight of your film and decided if this is possible. I have doubts.

There are weight scales which have a density determinations kit. It works by first weighing your sample, then use archimedes principle (put it in a liquid which does not swell or dissolve it). Just add enough of your film so that you get some accuracy.

Use AFM

Dear Bambang Soegijono, are you serious? How do you measure density with the AFM?

XRR is better if it is a single film. For multilayers its not perfect as it takes the average values of refractive indices to give the critical angle from which density is derived.

Try to measure the weight of your substrate as accurate as possible.

Deposit a thick film, and measure the weight. You must know the thickness of the film fairly accurately..

This way you can get an approximate idea of the density of the film.

K. Sreenivas

I suggest xrr is better technique

Would you be able to clarify how you did it in the end? It is impossible when you don't have enough material to do Archimedes method and I have also tried doing densitometry with helium again with no result. Is there any real method to measure thin films? Thanks everyone

I would also agree that XRR gives an answer with good accuracy if the measurements is done properly. Other methods include using IR transmission as illustrated by article by Laux et.al. https://www.osapublishing.org/ao/abstract.cfm?uri=ao-35-1-97

XRR and weight estimation both are good techniques for film density calculation. You can also compare both these results and see the difference. you can also use transmittance spectra because film density is a measure of the light-stopping ability of thin films and is related to the opacity and transmittance of the film.

X-ray reflectivity is a good start

https://www.researchgate.net/post/Measuring_density_of_thin_films-can_anyone_help

Yes, i think so ...XRR is good one.