CC BY SA is the best license to use for research. It's like the GPL, but for non-software works. What's not to love about that? It's definitely a freedom-respecting license.
What do you mean by "public domain"? Many countries don't have a concept of a public domain (or it's not as well-established as in America). If you actually wanted to release it as public domain (or as close as possible) then use CC0.
But I still stand by saying that CC-BY-SA is the best license for academic works because it ensures that the work is always useful to future generations.