The reference Rosenblad C, von Kanel H, Kummer M, ¨Dommann A, Muller E 2000 ¨ Appl. Phys.
Lett. 76 427 was omitted from the reference list and should have been cited in the first sentence of section 3, after ‘We have analyzed a series of SiGe/Si(001) graded layers prepared at ETH Zurich, Switzerland by an LEPECVD (low energy plasma enhanced chemical vapor deposition) method at different temperatures’.