Vibrational properties and infrared dielectric features of Gd2CoMnO6 and Y2CoMnO6 double perovskites. Issue 4 (March 2019)

• Record Type: Journal Article
• Authors: Silva, R.X.; Almeida, R.M.; Moreira, R.L.; Paniago, R.; Rezende, M.V.S.; Paschoal, C.W.A.
• Is Part Of: Ceramics international. Volume 45:Issue 4(2019)
• Page Start: 4756
• Page End: 4762
• Publication Date: 2019-03
• Subjects: Dielectric properties -- Magnetodielectrics -- Double perovskites -- Infrared spectroscopy -- Microwave ceramics; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.11.168
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Gd2 CoMnO6 and Y2 CoMnO6 double perovskite ceramics were obtained from the polymeric precursors method and investigated by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Raman and Fourier Transform Infrared (FTIR) spectroscopies. Our results show that these samples present similar structural and vibrational characteristics that are fully compatible with a monoclinic structure belonging to the P21 /n space group, with ordered Co 2+ and Mn 4+ cations. Infrared-reflectivity spectroscopy was employed to investigate the polar phonon features and to determine the intrinsic dielectric response of the materials. In particular, the extrapolated dielectric constants at the lower frequency infrared limit showed to be independent on the particle size, and were determined as ε ′ intr ≈ 17.8 and 16.0, for Gd2 CoMnO6 and Y2 CoMnO6, respectively. Otherwise, it is shown that for smaller RE radius the FTIR bands become more evidenced, due to a higher octahedral rotation and lower < Co-O-Mn > angle into the distorted monoclinic structure.