Magnon and Phonon Excitations in Nanosized NiO

By Ņ. Mironova-Ulmane, A. Kuzmin, I. Sildos, L. Puust, J. Grabis. Latvian Journal of Physics and Technical Sciences, 2019

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Abstract Single-crystal, microcrystalline and nanocrystalline nickel oxides (NiO) have been studied by Raman spectroscopy. A new band at ~200 cm−1 and TO-LO splitting of the band at 350–650 cm−1 have been found in the spectra of single-crystals NiO(100), NiO(110) and NiO(111). The Raman spectra of microcrystalline (1500 nm) and nanocrystalline (13–100 nm) NiO resemble those of the single crystals. They all contain the two-magnon band at 1500 cm−1, indicating that the oxides remain at room temperature in the antiferromagnetic phase. Besides, a new sharp Raman band has been observed at 500 cm−1 in nanocrystalline NiO. Its temperature dependence suggests the magnetic origin of the band, possibly associated with the one-phonon–one-magnon excitation at the Brillouin zone centre.

Subfields: Electronic, Optical and Magnetic Materials, Materials Chemistry, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/6624055dc4bc8128685f73abdf11f00712d6bbf6