Evidence of competition in the incorporation of Co 2+ and Mn 2+ ions into the structure of ZnTe nanocrystals

• Published in: RSC advances 2016, Vol.6 (103), p.101226-101234
• Main Authors: Silva, Alessandra S., Pelegrini, Fernando, Figueiredo, Leandro C., de Souza, Paulo E. N., da Silva, Sebastião W., de Morais, Paulo C., Dantas, Noelio O.
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA19189D

Glass-embedded Zn 1−x−y Mn x Co y Te nanocrystals (with x = 0.01 and y varying from 0.000 to 0.800) were successfully synthesized using a protocol based on the melting–nucleation synthesis route and herein investigated by several experimental techniques. Optical absorption (OA) provides evidence of the incorporation of substitutional Co 2+ ions in the semiconducting Zn 1−x−y Mn x Co y Te lattice and shows that with increasing Co concentration these ions may also be dispersed into the glass matrix, causing structural disorder. Atomic force microscopy (AFM) images reveal the size of the nanocrystals and magnetic force microscopy (MFM) gives evidence of the paramagnetic behavior of the doped samples. X-ray diffraction (XRD) and Raman scattering reveal that high Co concentrations increase the structural disorder in the host glass matrix. Electron paramagnetic resonance (EPR) spectroscopy reveals the presence of Mn 2+ ions inside and at (or near) the surface of the ZnTe nanocrystals, and also that the increase of Co doping concentration reduces the incorporation of Mn 2+ ions into the ZnTe structure, simultaneously increasing their dispersion into the glass matrix.