Hi everybody I have studied some papers in which, it is observed that the refractive index of specimens increases. authors attribute their findings to the increase of the crystallinity of samples (based on XRD patterns). Also, in some papers, it is observed that the refractive index of specimens increases. authors attribute their findings to the decrease of the crystallinity of samples. It seems that one of these interpretations is wrong. Is refractive index increases by increasing the crystalinity or decreases? thanks.