I use XRD to identify crystalline phases created in metallic glass film after heat treatment. In order to compare these crystalline phases, I quantify how much these phase is formed by calculating the area of these peaks. To do that, I first produce the background curve from the diffraction pattern by using Highscore software. The area below the background curve is considered amorphous phase while the area between the background curve and sharp peaks is crystalline phases. The percentage of each crystalline phase equal to the area of each peak divides the total area of diffraction pattern. My questions are

1. By using software, we can easily to create the background curve and then find peaks. However, what is the principle of creating background curve in the diffraction pattern ? How high and sharp of peaks is considered as crystalline peaks ?

2. The way I quantify the percentage of crystalline phases above is correct or not ?