We report on the synthesis, structure and magnetic properties of a novel exchange bias
system with Cr2O3/CrO2/Cr2O5 interfaces. Chromium oxide particles with mixed chromium
valences were prepared by sintering CrO3 in air. X-ray diffraction patterns show that CrO3
lost its oxygen gradually with increasing temperature and time through Cr3O8, Cr2O5, CrO2,
and finally Cr2O3 at temperatures above 760K. X-ray photoelectron spectra indicate a low
CrO2 content and a binding energy of 579.3 eV for Cr 2p3/2 photoelectrons in Cr2O5 …