X-ray patterns were collected with a Philips powder
diffractometer with a Bragg–Brentano geometry and
equipped with a copper anode operated at 40 kV and
30 mA (step 0.02°, time 6 s). The phase analysis was
carried out with the PC X’pert High Score software
Version 2.2a (PANalytical B.V., Almelo, the
Netherlands).