Synthesis, crystal structure and magnetic properties of the spin ladder compounds La2(Cu1−xZnx)2O5 and La8(Cu1−xZnx)7O19

Crystal structures of spin ladder compounds La8Cu7O19 (5-leg) and La2Cu2O5 (4-leg) (bright circles: lanthanum; in the middle of the polyhedra: copper; polyhedra vertices: oxygen).