In this paper, the determinations of Al composition x of
(0⩽x⩽1) thin films by means of the energy dispersive X‐ray (EDX) and X‐ray diffraction
(XRD) analyses are reported. Through these non‐destructive and contactless techniques, a large probed area of the
samples can be selected. Consequently, the uncertainty due to the inhomogeneity of the Al composition can be avoided. For EDX measurements, the Al composition is calculated based on the weight percent of the Al and Ga elements, while that in the XRD measurements is based on lattice constant
c and Vegard’s law. The results from these two independent techniques are in good agreement with each other.