Synthesis and Characterization of some Nanomaterials Doped with some Transition Metals

Abstract

Prepared Cd1-x TMxO where TM (Transition metals) (TM= Co, Cr, Cu, Mn, Fe and Ni) and (x=0.1) in two formsnanopowder and thin film by two methods Co-precipitate for nanopowder samples and Sol-Gel for thin film samples.XRD pattern for nanopowdersamples have crystalline nature, the grain size is 47.62nm for undopedCdO and about 47.65 to57.07nm for doped CdO. The values of grain size and strain and dislocation density increase with adding transition metals.The values of glass transition temperature (Tg) of investigated samples decrease with adding transition metals; this means that the stability of the investigated samples decrease. The reflectance of the nanopowder samples increases with increasing the wavelength. The band gap energy (Eg)is 2.007eV with direct transition, the values of (Eg) increase with the addition of TM, this effect are frequently observed in n-type semiconductors. The width of tails of the localized states in the gap (Es)decreases with the addition of TM, it represents the decrease of disorder. The refractive index (n), the dielectric constant (ε1), the dielectric loss (ε2) and the dielectric relaxation time (τ) was estimated for nanopowder samples. The agglomeration increases due to the decrease in surface area for the thin film samples. XRD pattern for thin samples have polycrystalline structure; the grain size forCdO thin film is 8.23nm; the unit cell volume is reduced with adding transition metals; the strain, the dislocation density and lattice parameter were estimated. the transmittance of thin films increases by adding due to the absorbance decreases by free carriers; the band gap energy (Eg), the refractive index (n), the dielectric constant, the dielectric losses and the optical conductivity were estimated for thin film samples. The electrical conductivity decreases with temperature and with adding transition metals. The majority carriers are electrons, which proved that CdO thin films are n-type semiconductors. The hall coefficient (RH) and mobility were estimated. The ac conductivity for single-electron motion undergoing Overlapping Larger Polaron Tunneling (OLPT) with polaron radius (r0=2.5). The general trend of dielectric constant (ε1) at applied selected frequencies is decreasing for CdO thin film and is increasing temperature. CdOundoped and doped TM/Si Substrate are good diode, MnCdO/P-Si heterojunction act as a good candidates for the production of high- efficienyphotodectors; the ideality factor (n), the effective potential barrier height (φB0), the series resistance (Rs) and optoresponse (S*curr) were estimated.