Room temperature dilute magnetic semiconductor response in (Gd, Co) co-doped ZnO for efficient spintronics applications

Abstract

The co-precipitation approach was utilized to experimentally synthesize ZnO, Zn_0.96Gd_0.04O and Zn_0.96−xGd_0.04Co_xO (Co = 0, 0.01, 0.03, 0.04) diluted magnetic semiconductor nanotubes. The influence of gadolinium and cobalt doping on the microstructure, morphology, and optical characteristics of ZnO was investigated, and the Gd doping and Co co-doping of the host ZnO was verified by XRD and EDX. The structural investigation revealed that the addition of gadolinium and cobalt to ZnO reduced crystallinity while maintaining the preferred orientation. The SEM study uncovered that the gadolinium and cobalt dopants did not affect the morphology of the produced nanotubes, which is further confirmed through TEM. In the UV-vis spectra, no defect-related absorption peaks were found. By raising the co-doping content, the crystalline phase of the doped samples was enhanced. It was discovered that the dielectric response and the a.c. electrical conductivity display a significant dependent relationship. With the decreasing frequency and increasing Co co-dopant concentration, the ε_r and ε′′ values decreased. It was also discovered that the ε_r, ε′′, and a.c. electrical conductivity increased when doping was present. Above room temperature, co-doped ZnO nanotubes exhibited ferromagnetic properties. The ferromagnetic behaviour increased as Gd (0.03) doping increased. Increasing the Co content decreased the ferromagnetic behaviour. It was observed that Zn_0.96−xGd_0.04Co_xO (x = 0.03) nanotubes exhibit superior electrical conductivity, magnetic and dielectric characteristics compared to pure ZnO. This high ferromagnetism is typically a result of a magnetic semiconductor that has been diluted. In addition, these nanoparticles are utilized to design spintronic-based applications in the form of thin-films.