Mn-Doped CdO Nanocrystalline Particles: Structural and Electrical Properties Modulation

Cadmium oxide (CdO) has been recognized as a promising diluted magnetic semiconductors (DMSs) for its various applications in spintronics, high sensitivity gas sensors and electrochemical sensors, etc. The present work reports the synthesis, structural, magnetic and dielectric properties of pure CdO and Mn-doped CdO nanoparticles with Mn-content (x = 7%) which were synthesized using simple co-precipitation method. Structural analysis via X-ray diffraction patterns revealed a cubic crystal structure in all materials, with no discernible impurity phases. FESEM images indicated a reduction in the grain size of CdO after doping of Mn-content. Magnetic measurements revealed a superparamagnetic behavior in CdO with magnetization (0.05 emu/g) at 5 K temperature and this superparamagnetic ordering was notably augmented through Mn-doping with magnetization (0.5 emu/g). In M(T) curves, blocking temperature (T_b) showed the transition from ferromagnetic to super paramagnetic behavior, also confirmed the presence of superparamagnetic behavior at low temperature in these nanoparticles. The dielectric constant is 25 × 10² and electrical conductivity is 5 × 10^–5 Ω^–1 cm^–1 of CdO. Both are found to increase (dielectric constant 22 × 10³ and electrical conductivity 15 × 10^–5 Ω^–1 cm^–1) after doping of Mn-content, may be due to increase in free charge carriers.