Investigation of the Optical, Electric Properties, and Conduction Mechanism of the Cubic Spinel LiMn₂O₄

ABSTRACT LiMn 2 O 4 spinel was prepared via a solid‐state process. Powder XRD results revealed the formation of a single cubic phase structure with the grain sizes of 0.13 μm. The cubic spinel LiMn 2 O 4 crystallized in the three‐dimensional (3D) frameworks of the MnO 4 and LiO 4 tetrahedra units. The optical study presents a band gap around 2.57 eV. We studied the stability of lithium‐manganese oxides using electrical impedance over a temperature range of 323 to 453 K. The AC electrical conductivity is on the order of 10 −3 –10 −2 Ω·cm −1 , confirming the semiconductor character of the material and indicating its importance in optoelectronic and energy storage devices. The variation of the exponent s indicates its significance, demonstrating that the overlapping small polaron tunneling (NSPT) conduction model describes the two phases of this material.