GIXRD (Shimadzu XRD 6000) was performed with 2° incidence angle, enabling phase identification of the uppermost 600 nm of the sample. The GIXRD patterns were interpreted by comparison with the cards of the Powder Diffraction File™ (PDF) from the International Center for Diffraction Data (ICDD®). Riet veld analysis was performed with the FullProf Suite software [19].