A facile synthesis and spectral characterization of Cu2+ doped CdO/ZnS nanocomposite

• Cu2+ doped CdO/ZnS nanocomposites were synthesized by a two-step wet chemical method.
• XRD study describes the crystallite size is in nano regime.
• Rhombically distorted octahedral coordination for Cu2+ ion with dx2−y2 as ground state.
• Ferromagnetism is due to spin-polarized and conduction electron interaction.

A facile two-step method is demonstrated for the preparation of Cu2+ doped CdO/ZnS nanocomposite. Systematic investigations like X-ray diffraction (XRD), Scanning electron microscopy (SEM) with EDS, transmission electron microscopy (TEM), FT-IR, electron paramagnetic resonance (EPR), optical absorption, photoluminescence (PL) and magnetic studies are carried out for the prepared material. From powder XRD, the nanocomposites are comprised for cubic phase of both CdO and ZnS in a close contact with each other. The ground state wave function of dopant ions has been estimated from EPR studies. Optical and EPR data confirm that doped Cu2+ions occupy rhombically distorted octahedral sites with the host material. Due to doping, band gap has been changed and blue shifts occurred in PL. Magnetic measurements indicate a possible ferromagnetic response, associated to the exchange interaction between local spin-polarized electrons of Cu2+ ions and conductive electrons.

M–H curve of Cu2+ doped CdO–ZnS nanocomposites.The magnetic properties of Cu2+ doped CdO/ZnS nanocomposite has been investigated using vibrating sample magnetometer given as magnetization and hysteresis (M–H) curve. The magnetization curve with noticeable coercivity of M–H loop clearly indicate the existence of ferromagnetic ordering in Cu2+ doped CdO/ZnS nanocomposite at room temperature. According to the Ruderman–Kittel–Kasuya–Yosida (RKKY) theory, the exchange interaction between local spin-polarized electrons (such as the electrons of Cu2+ ions) and conductive electrons is the main cause that leads to the ferromagnetism. Coercivity (Hc) of the field is about 98 Oe, saturationmagnetization (Ms) and remnant magnetization (Mr) of present sample is estimated to be 15.8×10−3 and 1.43×10−3 emu/g respectively. The ferromagnetism observed in the prepared material is not commencing with other impurities but expected to be intrinsic.Figure optionsDownload as PowerPoint slide