I have a phrase:
Investigation of catalytic phase structure using SEM and TEM methods
I always thought that "investigation of" is a correct way of saying it. But I am told that it is actually "investigation into".
Browsing the net, I could not find the answer about the difference of these two.
So my question is: does "investigation into" even exist, and if so, what's the difference between it and "investigation of", and where can each be used?