Structure, optical and transport properties of Mg-doped ZnMn₂O₄

The study deals with the effects of the Mg-doping on the structural, optical and electrical properties of ZnMn₂O₄. Mg_x-ZnMn₂O₄ is elaborated by Sol-Gel route at 700 °C. The X-ray diffraction profiles show the synthesis of a pure tetragonal phase over the whole 0–0.1% investigated range. No secondary clusters are detected. The attenuated total reflectance spectra position the Mg in octahedral sites. The extinction coefficient, optical conductivity, dissipation factor and the relaxation time are improved. The latter has been upgraded by 70%. The Hall Effect measurements confirm the conserved semi-conducting p-type. The Mg_Mn¹⁻ point defects are evidenced; however, an antagonist effect between the carrier concentration and the mobility is generated. - Highlights: • Mg_x-ZnMn₂O₄ spinels were successfully elaborated via Sol-Gel route. • The Mg atoms were localized on the octahedral sites. • The optical and electrical properties of ZnMn₂O₄ were improved thanks to Mg-doping. • A 70% enhancement of the charge-carriers' lifetime was achieved.