You should be aware that Li, Na and K are metals who are extremely soft (they can be cut with a simple spoon at room temperature), and which are ultrasensitive to oxidation, whether by air or moisture. Therefore, they can be handled only in a special glove box working with a flow of highly purified argon. Even in these conditions, handling is difficult. Considering their extremely poor mechanical strength, I understand that these metals can't be shaped as nano-objects, which are even more sensitive to oxidation than the bulk metals.

Alain

Dear Professor Alain Celzard, Thank you very much for your response. 

Yes, I am aware of all these problems. I was interested by some reports from Martin Blaber et al showing the potential of alkali metals (Li, Na, K) as plasmonic material. So, I was thinking whether there is any report on whether any body has fabricated in nano-scale. I have seen reports on films of Li and K but haven't found any report on Li/Na/K nanofabrication. But practically, I think, it would be even more difficult to preserve that or, make it practically useable even if it can be fabricated considering their very reactive properties 

Thank you again for your response. 

Looks this paper, I think, that appropriate for you problem.

http://www.sciencedirect.com/science/article/pii/S0022369712001199

Dr. Alexander N Titov, thank you very much for your kind suggestion. Yes, it has been very much helpful for me.

Best Regards