Photoinduced Electron Spin Resonance Phenomenon in α-Cr2O3 Nanospheres

Abstract EN

The photoinduced phenomenon in α-Cr2O3 nanoscaled spherical particles was investigated in the temperature range of 150 up to 315 K.

An X-band electron-spin resonance spectrometry was employed to probe the magnetic behavior in α-Cr2O3 under an IR illumination in the nanosecond regime.

The photoinduced effect on both low and high field ESR signals appears above 280 K and is remarkably enhanced just below Néel temperature TN.

Such a photoinduced ESR phenomenon disappears in a reproducible way in the paramagnetic insulating state which occurs above TN of crystalline α-Cr2O3.

In the antiferromagnetic phase, that is, below TN, the shift of the low field absorption could be attributed to the interaction of the light with specific Cr3+ ions located in strongly distorted sites correlated to strong ligand-field effect.