Yes (ok) he talks about the concept of master/slave morality in Beyond Good and Evil but he talks about a lot of other stuff in that book. He also talks about it in Human, All Too Human and probably other places. I don't remember off the top of my head. But where he explores it at length is in On the Genealogy of Morals. The title's a bit of a giveaway. I've read Beyond Good and Evil a number of times, and I'm sure I'll read it many more times before my number is up, I don't need you to tell me that :-)
The only bit of Heidegger I'm going to read is his where he talks about technology. Other than that I'm going to give him a wide enough berth because I don't like his writing style. He can be as profound as he likes and he can destruct whatever ontologies he's into but after having flipped through a bit of Being and Time I have to say no thanks.
And in fairness destruktion is not de_construction_. You still haven't told me where to look it up though. Chapter and verse and all that, no?
edit: ok, so FreakLegion[1] hereabouts has some pointers and I used my Google-fu and got this[2] which looks helpful. But even that says that Derrida got inspiration but that the terms are not used in the same sense.