I read somewhere about mag-fluoride as well. Also,
I guess I meant adhesion properties.. (is adhesive the same thing?). I've been reading up on the science of interfaces between materials and came across some literature on mechanical interlocking interfaces, where the substrate material has "digs" or "voids" that get filled in with the coating material, thereby giving better adhesion. Not sure how those digs are made, or if it's done with CaF2, but it sounds interesting.