Pristine and metal-doped cobalt aluminate samples were well synthesized using the sol–gel auto-combustion method. The physical properties of the synthesized samples were investigated employing X-ray diffraction and Raman spectroscopy. To validate structure stability, the influence of lattice strain was carried out by comparing Debye–Scherrer’s and Williamson-Hall plot method. Furthermore, Rietveld analysis was performed for precise structural parameters. Four Raman active modes (T_2g⁽²⁾ + T_2g⁽³⁾ + E_g + A_1g) were examined within the range of 400 to 900 cm⁻¹, confirming the formation of spinel structure. Here, an anomaly of the quadruple splitting of A_1g mode in pristine and Zn²⁺-doped cobalt aluminate was observed. The FTIR spectroscopy shows metallic bonds confirming the absence of other functional groups. In UV–Vis spectroscopy, doping of Cu²⁺ (0.72 Å) and Zn²⁺ (0.74 Å) with nearly comparable ionic radii as Co²⁺ (0.72 Å), optical bandgap increases ranging from 3.1 to 4.29 eV. Further, Urbach’s energy was plotted for all samples. Results show that doping of Cu²⁺ and Zn²⁺ supports reducing local lattice distortion. These features improved stability and wide optical bandgap ensure a vital role in state-of-the-art applications.

使用溶胶-凝胶自动燃烧方法可以很好地合成原始和金属掺杂的铝酸钴样品。利用X射线衍射和拉曼光谱研究了合成样品的物理性质。为了验证结构的稳定性，通过比较Debye–Scherrer和Williamson-Hall绘图方法对晶格应变的影响。此外，对精确的结构参数进行了Rietveld分析。在400至900cm ^-1的范围内检查了四个拉曼活性模式（T _2g ^（2）  + T _2g ^（3）  + E _g  + A _1g），确认了尖晶石结构的形成。这里，A _1g的四重分裂异常原始模式和掺杂Zn ^2+的铝酸钴被观察到。FTIR光谱显示金属键，确认不存在其他官能团。在UV-Vis光谱中，掺杂的Cu ²⁺（0.72Å）和Zn ²⁺（0.74Å）的离子半径几乎与Co ²⁺（0.72Å）相当，光学带隙范围从3.1到4.29 eV。此外，绘制了所有样品的Urbach能量。结果表明，Cu ²⁺和Zn ^2+的掺杂有助于减少局部晶格畸变。这些功能提高了稳定性，宽的光学带隙确保了在最新应用中的重要作用。