Impact of gadolinium doping on structure, electrical and magnetic properties of Gd_xCd_1−xMnO₃ manganite nanoparticles

Nanocrystalline gadolinium-doped cadmium manganite having general formula Gd_xCd_1−xMnO₃ sintered at 960 °C for 10 h (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 and 0.7) were prepared by co-precipitation method. XRD, SEM, and EDS have characterized the structure of the studied material. Also, the DC electrical conductivity and magnetic properties are measured and analyzed. The effect of the MnO₆ octahedral structure on structural, electrical, and magnetic performance is investigated by doping of Gd-concentration and size misalignment of the A-sites cations by replacing Gd ions by Cd ions. With the pnma space group, all the samples have orthorhombic crystal structures. The range of crystallite sizes was 67.8 to 85 nm. SEM images showed that the average particle size within 73.23–214.3 nm for the studied samples. EDX demonstrates the presence of all the constituents of compounds. The variation in the DC conductivity above room temperature was studied and impressed with all compositions' semiconducting behavior. Moreover, the conductivity data were fitted using the small polaron hopping (SPH) model. The activation energy was calculated using the Arrhenius equation ranging from 0.18 to 0.46 eV. The magnetization curve (M–H) confirmed that the samples show paramagnetic behavior even at the high magnetic field. The Gd substitutions cause the increase average particle size and increase magnetization by 150%; on the contrary, it decreases the coercivity by 40%. The results suggest that using these compounds in potential oxygen sensor electrodes and resistive switching equipment is of interest. As applicants for biomedical applications, such benefits would also promise.