Dear colleague Bhasker Soni,

Have a nice time and good day.

To confirm the obtained results of optical gap increasing, you need to check the material under consideration by XRD, TEM, SEM and AFM. using the aforementioned techniques you may calculate the crystallite size from XRD and TEM and the grain size and the morphology using SEM and AFM,  the increasing values of the optical gap should be supported by the increasing of crystallite size and the improvement of surface morphology. So the XRD, TEM, SEM and AFM are needed to be used to confirm your obtained data.

I wish this is useful and help you.

Yours

A. EL-Denglawey 

Dear A. Eldenglawey sir: Thank you for your guidance. I have observed crystallite size to decrease with increase in dopant concentration. The average size were 6.6 nm, 4.4 nm, 4.8 nm, and 4.5 nm for 3%, 5%, 10%, 20% Gd doped CeO2. The same was confirmed with TEM.

I do not have AFM hence could not confirm with that. 

Regards,

Dear colleague Bhasker Soni,

Have a nice time and good day.

I have many questions concerning the obtained results. 

1-What is the experimental error of you results?

2- Is the obtained XRD peaks are sharp or broaden?

3- Did you extract the back ground of substrate from the obtained results?

Yours

A. EL-Denglawey