Hello Vaibhav,

I guess you're gonna have to try around a bit and it also depends on what you want to see. For KNN we obtained good results for the observation of grain boundaries and domains with HF even after some seconds of etching (provided the surface was well polished before).

Dear Dr. Thomas,

Many thanks for your kind reply. Hopefully this will help us. Could you please quickly comment on the exact etching time and etchent composition?

Thanks in advance...

Dear Vaibhav,

I attatched an image that shows an etched KNN sample. It was etched for 60s in 45% HF, but as I said, its just to give you an idea. It may be different for your materials.

Best of luck

Dear Dr. Thomas,

Many thanks for your response. Hope this will help us.

Dear Dr, Thomas,

Since we have dearth of understanding about etching process, we still need more clarification.

What does 45% HF means?

Is it (45ml HF + 100 ml Deionized water) or pure 45 ml HF solution?

Because we have carried out the etching of KNN at (100 ml water + 48 ml of HF) for 3 min but could not able to see anything except porosity under optical microscope.

I request you to reply as early as possible.

Thanks in advance..

How did you prepare the surface before etching? I suggest you should polish it down to particle sizes of 0.25 micron and perhaps even use vibrational polishing as a last step before etching. It may enhance your results. If you did that, you should get what you want with the etching you described above...