The structural and magnetization studies of Co-doped ZnO co-doped with Cu: Synthesized by co-precipitation method

Abstract

Co-and Cu-doped ZnO of nominal composition Zn 0.95 Co 0.05 O and Zn 0.94 Co 0.05 Cu 0.01 O were synthesized by a co-precipitation method in organic media. Rietveld refinement of X-ray diffraction data of the samples annealed at 725 K showed that they are single phase without any secondary phases. DC magnetization measurements of samples with Cu co-doping (Zn 0.94 Co 0.05 Cu 0.01 O) as a function of field at room temperature showed a ferromagnetic signature while the samples without Cu co-doping (Zn 0.95 Co 0.05 O) are paramagnetic in nature. Both the samples heated at 1075 K are found to be paramagnetic at room temperature. Resistivity measurements above room temperature clearly showed a semiconducting behavior with a decreased resistivity value for Zn 0.94 Co 0.05 Cu 0.01 O compared to Zn 0.95 Co 0.05 O and ZnO, confirming additional carriers in Zn 0.94 Co 0.05 Cu 0.01 O due to Cu co-doping. Our results are in agreement with a recent computational study that doping additional carriers are necessary for realizing room temperature ferromagnetism in Co-doped ZnO.

Giant stability of substituent Co chains in ZnO:Co dilute magnetic oxides

“…This supports well the experimental findings that additional Cu doping can achieve roomtemperature ferromagnetism in paramagnetic Co-doped ZnO. 23,25,26 In the Zn 13 Co 2 Cu 1 O 16 system the most stable configuration is the "fully scattered" configuration 5 with a FM coupling because of its lowest total energy. Its E f is lower by 23 meV/Co than that of the "compact" configuration 2 with a FM coupling, having the second lowest total energy.…”

Structural, Magnetic and Dielectric Studies on Strontium Substituted Nd2CuO4 System

“…It is observed that the intensity of magnetization varies linearly with the applied magnetic field for all the prepared compounds which reveals the paramagnetic nature of the resultant compounds [11,12]. In the earlier reports, it is identified that the parent compound Nd 2 CuO 4 exhibits paramagnetic nature [13] and the same is obtained for both parent and prepared compounds now.…”

Structural and magnetic properties of (In1−xFex)2O3 (0.0⩽x⩽0.25) system: Prepared by gel combustion method

“…[2][3][4][5][6][7][8][9][10] For practical spintronic applications DMS with Curie temperature, Tc, above RT are required. Many promising oxides like TiO 2 , ZnO and SnO 2 and III-V semiconductor GaN doped with transition metal ions have been reported to exhibit ferromagnetic behavior near or above room temperature, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] but the origin of ferromagnetism in these systems is poorly understood. Oxide systems based on host semiconductor with high solubility of magnetic ions are highly desirable to form thermodynamically stable magnetic semiconductors.…”