Enhanced thermoelectric properties in dual cation doped CuCrO2 nanocrystals mediated by magnon-carrier drag

•CuCrO2 compounds are best known for their optoelectronic as well as thermoelectric (TE) properties.•Mg alone doping enhances the conductivity while Mg-Ni double doping improves both Seebeck coefficient and conductivity.•Reduced thermal conductivity and improved thermoelectric figure merit of 0.099 are observed at Ni doping of 0.2 wt%.•The presence of Mixed grains in FESEM images substantiates the reduced thermal conductivity.•Augmented Seebeck coefficient of 423 µV/K due to magnon-carrier drag and enhanced conductivity of 2083 S/m due improved carrier concentration and mobility leading to power factor of 350 µW/mK2. [Display omitted] The open-layered CuCrO2 delafossite has received great attention in medium-range temperature thermoelectric applications. The addition of Ni with Mg upsurged the carrier concentration and effective mass by 10-20 times owing to the multiple conduction bands in CuCrO2 hence increased mobility of 38.21 cm2/Vs was achieved. The power factor obtained is 350 μW/mK2 for the CuCr(MgNi)O2 (Mg=0.5, Ni=0.2 wt%) at 700 °C, which is above two times the Mg alone doped CuCrO2 nanocrystals. The lowest thermal conductivity of 3.43 W/Km and the highest ZT of 0.099 were also obtained for the same sample. The augmented Seebeck coefficient of 423 μV/K due to magnon-carriers interaction in the Cr3+ site, the enhanced conductivity of 2083 S/m, and reduced thermal conductivity caused by decreased carrier-phonon interactions are the reasons for the enhanced power factor and improved thermoelectric figure of merit.