La₂CoMnO₆ double perovskite was synthesized by the solid-state reaction method, and its crystal structure was investigated using X-ray diffraction and Raman spectroscopy. The crystal structure of the study compound has been verified to possess monoclinic crystal symmetry, space group P2₁/n with the lattice parameters a = 5.53 Å, b = 5.48 Å, c = 7.77 Å, and β = 89.9°. The Raman spectrum shows two broad peaks, the high-frequency peak near 668 cm⁻¹ corresponding to the A_g stretching mode, whereas the low-frequency peak near 522 cm⁻¹ corresponding to the B_g anti-stretching and bending modes. The electronic and magnetic properties of pure and defective perovskite La₂CoMnO₆ have been carried out using the density functional theory (DFT). The result shows a ferromagnetic insulator character for pure perovskite; the ferromagnetic state is explained by super-exchange interaction between empty and half-filled e_g orbitals of Mn⁴⁺( \({t}_{2g}^{3}\) \({e}_{g}^{0}\)) and Co²⁺ (\({t}_{2g}^{5}{e}_{g}^{2}\)) via oxygen O²⁻. The valence band maximum (VBM) begins primarily from the p-states of oxygen atom and d-states of transition metal (Mn and Co), while the conduction band minimum (CBM) comprises both d-states of the M-site transition metal and f-state of lanthanum. The creation of oxygen defect leads to the lattice expansion due to a Coulomb repulsion between the Co atom and Mn atom as oxygen is no longer their nearest neighbor (NN). The oxygen vacancy also reveals a half metallicity character with a bandgap in the spin-up channel and a continuous band at the Fermi level in the spin-down channel. The calculated Curie temperature T_C decreased (pure T_c = 422 K and defective T_c = 378 K) as decreasing the bond angle Mn-\(\widehat{O}\) ₃-Co (pure Mn-\(\widehat{O}\) ₃-Co = 150.13° and defective Mn-\(\widehat{O}\) ₃-Co = 146.026°).

采用固相反应法合成了La ₂ CoMnO _{6双钙钛矿，并利用X射线衍射和拉曼光谱对其晶体结构进行了研究。}研究化合物的晶体结构经证实具有单斜晶体对称性，空间群 P2 ₁ /n，晶格参数a  = 5.53 Å，b  = 5.48 Å，c  = 7.77 Å，β  = 89.9°。^{拉曼光谱显示两个宽峰，668 cm -1}附近的高频峰对应于A _{g拉伸模式，而522 cm} ^-1附近的低频峰对应于B _g抗拉伸和弯曲模式。使用密度泛函理论 (DFT)对纯和有缺陷的钙钛矿 La ₂ CoMnO ₆的电子和磁性特性进行了研究。结果显示了纯钙钛矿的铁磁绝缘体特性；铁磁状态可以通过Mn ⁴⁺ ( \({t}_{2g}^{3}\) _\ ({e}_{g}^{ 0}\) ) 和 Co ²⁺ ( \({t}_{2g}^{5}{e}_{g}^{2}\) ) 通过氧气 O ²⁻ . 价带最大值 (VBM) 主要从氧原子的 p 态和过渡金属 (Mn 和 Co) 的 d 态开始，而导带最小值 (CBM) 包括 M 位过渡金属的两个 d 态和镧的f态。由于 Co 原子和 Mn 原子之间的库仑排斥，氧缺陷的产生导致晶格膨​​胀，因为氧不再是它们的最近邻 (NN)。氧空位还显示出半金属丰度特征，在自旋通道中具有带隙，在自旋通道中的费米能级处具有连续带。 随着键角 Mn- 的减小，计算出的居里温度T _C降低（纯T _c  = 422 K 和缺陷T _{c = 378 K）}\(\widehat{O}\) ₃ -Co (纯 Mn- \(\widehat{O}\) ₃ -Co = 150.13° 和有缺陷的 Mn- \(\widehat{O}\) ₃ -Co = 146.026° ）。