Fabrication and ethanol sensing of sol–gel grown zinc oxide powder: the effect of cobalt and copper doping

The effect of graphene and cobalt on ethanol sensing performance of ZnO based sensor prepared by sol-gel method

“…The origin of the strain is attributed to the substitution of doped ions or the attendance of vacancies (zinc and oxygen) within the structure that lead to various defects and change in the length and angle of the bonds. 24) The most stress was observed in the Zn sample (pure zinc oxide), indicating that by the addition of dopants, the strain values decreased. Based on relations 2-5, other relevant parameters were determined and given in Table II.…”

“…Since the ionic size of cobalt is smaller than zinc; it is possible for cobalt ions to replace zinc ions inside zinc oxide lattice. 24) The smaller ionic radius ensures that the main structure of zinc oxide does not change substantially and the lattice constants of doped samples would be close to that of ZnO. The lattice parameters of the samples were determined and compared with standard amounts that are represented in Table I.…”

“…The grains with lower surface energy can get bigger and the movement of atoms to the positions with lower surface energies facilitates this augmentation. 24) The FWHM values can provide valuable information. The FWHM presents a direct relation between the crystallite sizes and the lattice constants of the samples.…”

“…21) Based on the literature, the vibration peaks of most metal oxides present between 400 and 700 cm −1 . 24) Therefore, an enlarged view of FTIR analysis within 450-750 cm −1 has been plotted [Fig. 2(b)].…”

“…It is possible to determine different physical parameters such as strain, crystallite size, dislocation density, stacking fault, and specific surface area through XRD results; as follows: 24) ( )…”