2.3.3. X-ray Diffraction (XRD) Analysis

The XRD patterns of the samples were measured using a multipurpose X-ray diffractometer (SmartLab 9 kW system, Rigaku Co., Tokyo, Japan) in a 2θ range of 5–80°. During the analysis, the operating voltage and current were 40 kV and 40 mA, respectively, and the wavelength was 0.154 nm. The degree of crystallinity is the ratio of the sum of the deconvoluted crystalline peak area over the sum of the crystalline and amorphous deconvoluted peak area.

where A_cr and A_am are the integrated area of the crystalline and amorphous peaks, respectively. The integrated areas were calculated using the Origin Software (Origin Lab Co., Northampton, MA, USA).