We report two-dimensional correlation spectroscopy (2D-COS) analyses of the Raman spectra of NiO nanoparticles over a temperature range from 100 to 300 K. 2D-Raman correlation spectra suggest strong correlation of the phonon spectral intensity variation with the magnetic ordering in NiO nanoparticles. It is revealed that the antiferromagnetic ordering affects the TO phonon anisotropy in NiO nanoparticles. We elucidate the complex spectral features of two-magnon (2 M) bands by performing appropriate 2D-COS model simulations. Significant spin-phonon coupling in NiO nanoparticles is supported by our results. High energy magnon-magnon interaction tails are also found to be involved in the spin-phonon coupling. 2D-COS analyses provide rich information regarding the nature of the phonon and magnon excitations of NiO nanoparticles.
|Journal||Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy|
|State||Published - 5 Nov 2022|
Bibliographical noteFunding Information:
The measurements in this work were supported by Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (2020R 1A 6C 101B194). I.S.Y. acknowledges the financial support by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2021R1A6A1A10039823). X.B.C. was supported by National Natural Science Foundation of China (Grant Nos. 51902227, 11574241).
- NiO nanoparticles
- Phonon anisotropy
- Raman spectra
- Spin-phonon coupling
- Two-dimensional correlation spectroscopy