Identification of Cobalt Oxides with Raman Scattering and Fourier Transform Infrared Spectroscopy

详细信息    查看全文

• 作者：Yang Li ; Wenlan Qiu ; Fan Qin ; Hui Fang ; Viktor G. Hadjiev ; Dmitri Litvinov ; Jiming Bao
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：March 3, 2016
• 年：2016
• 卷：120
• 期：8
• 页码：4511-4516
• 全文大小：422K
• ISSN：1932-7455

文摘

Although Raman spectral fingerprints of Co₃O₄ have been well established, the infrared spectrum of Co₃O₄ is less understood due to its dependence on sample morphologies and experimental configurations. The same is true for both Raman and infrared spectra of CoO. In this study, we present a comprehensive optical characterization of Co₃O₄ and CoO with Raman scattering and Fourier transform infrared spectroscopy (FTIR). Two of the transverse optical (TO) phonons and their corresponding longitudinal optical (LO) phonons of Co₃O₄ above 500 cm^–1 are observed in both transmission and diffuse reflectance with LO/TO intensity ratios depending on particle size and the incident angle of FTIR beam. CoO is featured by a broad infrared band around 510 cm^–1. In contrast to many previous reports, no Raman-active phonon line is observed, which is in agreement with the selection rule for rock-salt CoO. Nevertheless, CoO can still be characterized by Raman scattering from magnetic excitations in its antiferromagnetic phase at low temperature and a two-phonon Raman band at ∼1060 cm^–1.