On the correlation between electrical, optical and magnetic properties of Zn1−xPrxO nanoparticles

Abstract

We report here the structure, electrical, optical and magnetic properties of Zn1−xPrxO nanoparticles with various x values (0.00 ≤ x ≤ 0.50). X-ray diffraction pattern revealed wurtzite structure for all samples with an additional unknown peak formed at 2Ɵ = 28° for Pr = 0.00, 0.05, 0.10 samples. The cell parameters and dislocation density are increased with increasing Pr up to 0.30, followed by a decrease at Pr = 0.50. While a little bit decrease in the average grain size and an increase in the ZnO bond length are obtained. The nonlinear coefficient β, breakdown field EB and barrier voltage Vab are gradually shifted to lower values as Pr increases. They are decreased from 31.3, 2333 V cm−1 and 0.005 V for ZnO to 8.9, 750 V cm−1 and 0.001 V for 0.50 of Pr. The electrical conductivity versus temperature shows two conduction mechanisms and it is generally increased by increasing Pr and temperature. The conduction mechanisms are obtained at a temperatures width of (300–540 K) and (540–620 K), respectively. The activation energy Ea is decreased from 0.42 eV to 0.13 eV by 0.50 of Pr in the first region, while it is increased from 0.42 eV to 0.93 eV in the second region. The optical band gap Eg and exaction photon energy Eex are decreased by increasing Pr up to 0.50. They are decreased from 3.1 eV and 3.4 eV for ZnO to 1.62 eV and 2.79 eV by 0.50 of Pr, while Urbach energy Eu increased from 0.32 eV to 1.13 eV. Magnetization curves revealed room temperature ferromagnetism (RTFM) as Pr increases. The coercivity of the field Hc, saturated and remnant magnetization, magnetic moment are also increased by Pr up to 0.50. Our results are discussed in terms of oxygen vacancies, the density of states and local spin-polarized electrons exhibited by Pr as a dopant to ZnO.