An 57Fe Mössbauer effect study of magnetic ordering in the Fe2O3Cr2O3 system

摘要: Abstract 57Fe Mossbauer effect spectra have been obtained as a function of temperature for series Fe2O3Cr2O3 compositions in the range 0.2–75% Fe2O3. From 30% Fe2O3 upwards, dependence reduced internal magnetic field H eff (T) (T = 0) on temperature, T N , was found to be identical with that α-Fe2O3, indicating persistence Fe2O3-type ordering over this composition range. For 0.2% 57Fe2O3 Cr2O3, values fall far below those α-Fe2O3 or and weak coupling Fe3+ Cr3+ has inferred. A Morin transition similar not present samples containing 75% Quadrupole shifts ϵ were negative diminishing between 75 Fe2O3, positive 20 0.2%. The limiting value at lowest dilution 0.113 ± 0.010 mm/sec corresponds nuclear quadrupole constant e2qQ 0.45 0.04, approximately half α-Fe2O3. Cone angles spin vectors spin-spiral arrangements intermediate derived, are to, but less extreme than deduced from neutron diffraction data.