Magnetic-order induced effects in nanocrystalline NiO probed by Raman spectroscopy

Article

关键词: SPIN-LIQUID;    GROUND-STATE;    LN;    ANYONS;    PHASE;   

DOI  :  10.1103/PhysRevB.102.024423

来源: SCIE

【 摘 要 】

The magnetic-order induced effects in nanocrystalline NiO are investigated through the phonons and magnons observed in the Raman spectra. The key observations are (i) an anisotropy of the first-order transverse and longitudinal optical phonons, with a splitting on the order of 5 meV and (ii) a marked size and excitation wavelength variation of the two-magnon peak, which varies linearly with a redshift of similar to 50 cm(-1) with a size reduction from 105 to 30 mm The magnon-related peaks, in contrast to the phonons, are suppressed for near-resonance laser excitations. The experimental results are interpreted in terms of the exchange interactions and strong electron-electron correlations. The magnetization measurements shows a crossover to ferromagnetism with large coercivities and magnetization with decreasing size, which is shown to be due to the thermoinduced contribution.

【 授权许可】

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