## 3 Results and Discussion  
### X-ray Diffraction Analysis  
The X-ray diffraction (XRD) technique was used to explore the structural characteristics of the Mg-doped AlSb thin films. The crystallite grain size was calculated by using the Debye-Scherrer formula [16] as:  
\[\mathrm{D}=\frac{\mathrm{k}\lambda}{\beta\cos\theta} \tag{1}\]  
where D represents the crystallite grain size, K = 0.94, wavelength of X-ray source (Cu) \(\lambda\) = 1.54059 A\({}^{\circ}\), \(\beta\) is the full width half maximum (FWHM), which represents the broadening of diffraction line at half of its maximum intensity, and \(\theta\) represents the Bragg's angle. In addition, the dislocation line density was estimated using the formula \(\delta\) = 1/D\({}^{2}\)[17]. The XRD patterns of the intrinsic AlSb thin films, which were synthesized by varying the substrate temperature in the range of 72 \({}^{\circ}\)C \(\pm\) 3 \({}^{\circ}\)C are illustrated in Figure 1, along with the time variation from 1 to 3 h with a 30-min time step. The graph shows no peak sharpness at time intervals of 1 h, 2 h, 2.5 h, and 3 h, which proved the deposited AlSb thin film was amorphous in nature, while the XRD of the intrinsic AlSb at 1.5 h of deposition time confirmed its polycrystalline nature by the number of peaks observed at various angles along with various planes of reflection. Hence, we will briefly discuss here only the crystalline structures observed at 1.5 h of deposition time. Moreover, the hums present in the peak pattern were due to the glass substrate. These XRD structures and the conclusions drawn from them are consistent with the previous research [1]. Figure 1, showing the XRD patterns of pure AlSb thin films, demonstrates that an AlSb sharp peak was detected at an angle of 54.4\({}^{\circ}\) with a plane of reflection value of (023), confirming the cubic structural plan of AlSb thin films [1,18]. The grain size of AlSb film was reported as 0.46 nm, while the dislocation line density peak was measured as 4.6134 \(\times\) 10\({}^{18}\) m\({}^{-1}\) with a d-spacing value of 1.6853 A\({}^{\circ}\). Moreover, the single-crystalline nature of the AlSb thin film was also confirmed by the XRD patterns. Table 1 summarizes the XRD characteristics of pure AlSb for a 1.5-h deposition time along with the Sb data for planes (004), (112), and (102). Figure 1: XRD patterns of pure AlSb thin films for 1–3 h.  
Figure 2 demonstrates the 10% Mg-doped AlSb thin film XRD patterns at varying deposition time intervals of 1-3 h. The XRD pattern shows no sharp peaks for the deposition times of 1 h and 3 h, indicating the amorphous nature of AlSb thin films at these times; whereas the results for deposition times of 1.5 h, 2 h, and 2.5 h revealed a number of sharp peaks, indicating the crystalline nature of the doped AlSb films at these time durations, and only these specific deposition times are briefly discussed with reflection planes and other considerable parameters. The XRD parameters summary for the 10% Mg-doped AlSb thin film deposition times of 1.5 h and 2 h is shown in Table 2.  
Figure 2 depicts the Sb sharp peak observed at an angle of 23.7\({}^{\circ}\) at deposition times of 1.5 h and 2.5 h, as well as the reflection plan at the value of (003), which showed grain sizes of 0.29 nm and 0.23 nm, respectively, depending on the deposition time rate, with a relative intensity of 100% in both cases. However, increasing the deposition time increased \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Peak No.** & **20 (Degree)** & **D (A\({}^{\circ}\))** & **Hkl** & **Intensity (I)** & **FWHM** & **G.S (nm)** &
\begin{tabular}{c} **Dislocation Line Density** \\ **(m\({}^{-1}\times\)10\({}^{18}\))** \\ \end{tabular} \\ \hline
**1** & 54.4 & 1.6853 & (023) & 54.4 & 0.625 & 0.46 & 4.6134 \\
**2** & 27.7 & 3.2182 & (102) & 27.7 & 0.78 & 0.62 & 2.5407 \\
**3** & 32.1 & 2.7864 & (004) & 32.1 & 0.77 & 0.19 & 0.2739 \\
**4** & 46.2 & 1.9635 & (112) & 46.2 & 0.625 & 0.49 & 0.4039 \\ \hline \hline \end{tabular}
\end{table}