Photo electrical and optical anomaly in ferromagnetic cobalt doped ZnO nanostructures

• Published in: Physica scripta Vol. 90; no. 6; pp. 65503 - 8
• Main Authors: Zia, Amir, Ahmed, S, Shah, N A, Khan, E U
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.06.2015
• Subjects: Anomalies; Cobalt; Devices; Ferromagnetism; Magnetization; Nanostructure; nanostructured; photoconductive; remanence; sensors; Unit cell; Zinc oxide
• ISSN: 0031-8949; 1402-4896
• DOI: 10.1088/0031-8949/90/6/065503

For the development of novel devices, the correlation of oxygen vacancies and room temperature ferromagnetism in cobalt doped zinc oxide nanostructures synthesized by Co precipitation route reported earlier Zia et al (2014 Phys. Scr. 89 105802) has been further explored on the basis of structural, optical, magnetic and photoelectrical measurements. In the current study, x-ray diffraction data is further exploited for the measurement of d-spacing, c-direction growth for the plane (002) and cell volume. Increased volume of the unit cell is observed with the increase in cobalt content. UV-visible absorption spectroscopy analysis reveals the reduction in optical energy band gap with the increase in cobalt concentration. The saturated and remanence magnetization were found to be increasing with cobalt addition during the magnetic analysis. The photoelectrical conductivity has maximum value for the sample Co (3% mol) and least recovery time as compared to Co (0% mol). The sensing response was found to be decreasing with the addition of cobalt. The anomalies in the photoelectric parameters clearly reflect the presence of photoconductive nature, which may have ramifications for device engineers.