Raman and EPR Characterization of Diluted Magnetic Semiconductor Sb₂–ₓMnₓS₃ Nanocrystals Grown in a Glass Matrix

• Published in: Journal of physical chemistry. C Vol. 123; no. 9 p.5680-5685; pp. 5680 - 5685
• Main Authors: Silva, R S, Guimarães, E V, Cano, N F, Rosa, R H, Mikhail, H D, Silva, A C A, Dantas, N O
• Format: Journal Article
• Language: English
• Published: 07.03.2019
• Subjects: crystal structure; electron paramagnetic resonance spectroscopy; glass; ions; magnetic properties; magnetism; manganese; nanocrystals; Raman spectroscopy; semiconductors; transmission electron microscopy
• ISSN: 1932-7455
• DOI: 10.1021/acs.jpcc.8b10539

Structural and magnetic property change for different Mn concentrations in diluted magnetic semiconductor Sb₂–ₓMnₓS₃ nanocrystals grown in a glass host matrix were investigated. Transmission electron microscopy images and energy dispersive X-ray analyses and Raman spectra with the modified model confirm the size and composition of nanocrystals. Electron paramagnetic resonance shows six hyperfine lines of the electron states, which are attributed to the interaction between the electron spin (S = 5/2) and the nuclear spin (I = 5/2) of Mn²⁺ ions (3d⁵) located in the crystal field of Sb₂S₃ semiconductor. Also, a change in Mn–Mn interactions is observed as Mn concentration increases. The blueshift of the Raman band around 188 cm–¹ with increasing Mn concentration gives strong indications of the substitution of Mn²⁺ ions for Sb³⁺ ions in the crystalline structure of Sb₂S₃. In addition, the band around 217 cm–¹ remains constant for Mn concentrations of 0.00–0.10. However, for x = 0.20, a displacement of 210 cm–¹ occurs, which indicates an interstitial incorporation of Mn ions in the Sb₂S₃ structure at high Mn concentrations. A Raman high-frequency “shoulder” mode at 339 cm–¹ is observed. Therefore, in this work, Sb₂–ₓMnₓS₃ nanocrystals were grown successfully.