Dear Rana

I agree that doping means that there is some sort of solid solution or, at least, a modification takes place on the the grain boundary lattice. Thus, the chemistry of the grain boundary is essentially unchanged but the physical properties, e.g. grain boundary mobility is changed. Usually, doping is ranges from several ppm to 100 ppm.

While addition, frequently 100 ppm and more, is accompanied with noticeable change in the grain boundary chemistry; often accompanied with a thin film or layer. This will substantially alter the behavior of the grain boundaries in many aspects, especially in the course of sintering process.

Rana... Doping is usually performed during the preparation of the material where the dopant material is present and co-crystallized with the main material. Thus, that there will be a uniform distribution. Addition is usually a physical process where the two materials are mixed in the solid state or from a suspension to give a mixture rather than a uniformly doped material. Thus, the crystal of the main matrix material will include the dopant atoms within the structure, while the crystal structure of the two materials will be preserved by the addition process. addition... Hopefully, the answer will be adequate. ..Good luck. 

Dear Dr. Mahmood

Thank you so much.

Dear Rana... You'r welcome... Regards... Mahmood

Dear Dr. Rana,

If it goes into the lattice (solid solution) of parent materials then you can say it as doping. There are few criteria to get solid solution. For example when you add Y2O3 in ZrO2, it makes solid solution with ZrO2. Here, Y2O3 is dopant. However, if it does not make SS, then it will be a second phase in the composite considering it does not react with the parent matrix material. Now while doing spot analysis in SEM-EDS it is difficult to say whether the signal is coming from solid solution or from small second phase. In SEM due to elemental contrast you may see the second phase in BSE mode. Then it will be easier for you to conclude. XPS may help you in this regard. Also, if you do XRD you can see the change in lattice parameter for doped and undoped materials. Combination of characterization techniques always helps in conclusion.

I am not sure whether I have answered you query properly.

Dear Dr.Rana:

In doping, the dopant  enters the lattice of the main material so you have or you can observe only  one lattice. In addition, you have two lattice.For example in XRD, you have only one observed pattern in the case of doping.

Dear Rana

I agree that doping means that there is some sort of solid solution or, at least, a modification takes place on the the grain boundary lattice. Thus, the chemistry of the grain boundary is essentially unchanged but the physical properties, e.g. grain boundary mobility is changed. Usually, doping is ranges from several ppm to 100 ppm.

While addition, frequently 100 ppm and more, is accompanied with noticeable change in the grain boundary chemistry; often accompanied with a thin film or layer. This will substantially alter the behavior of the grain boundaries in many aspects, especially in the course of sintering process.

Dear Dr. Saad

Thanks so much for your response and answer.

Best Regards

Rana Anaee

Dear Rana

http://seas.yale.edu/news-events/news/new-doping-method-improves-electronic-properties-carbon-nanotubes

Thanks for the clarification. I also had the same question.

Dear Rana,

doping = addition

Doping is a process of adding an impurity into base material.

Doped material = not pure any more contains impurity.

A question whether the impurity changes some properties or not is the secondary one. May be some amount does not change anything in properties. For different materials the amount of impurity to change some propeties in base material will be different.

You can use the word you like but in a paper do always make it explicit what do you understand under this particular word.

Anton

I agree with Prof Dr. Mahmood M. Barbooti