X-ray diffraction (XRD) traces were obtained from the powdered samples using a Siemens (D500, Siemens, Karlsruhe,
Germany) diffractometer. Ni-filtered CuK α radiation was used and the operating conditions were 40 kV/30 mA, 0.02θ/(2θ) step scan at 1° (2θ)/min, 1° divergence and receiving slits and a 0.15° scatter slit. A scan range of 5° to 50° (2θ) was used.