Magnetic ordering in CocMg1−cO solid solutions

The influence of dilution by diamagnetic ions on the magnetic ordering in single-crystal Co c Mg1−c O solid solutions was studied by Raman spectroscopy and magneto-optical microscopy in a wide range of temperatures (6 < T < 200 K). Far infrared absorption measurements of antiferromagnetic resonance (AFMR) were also performed for pure CoO. It was found that the domain structure and the contribution from Brillouin zone center magnons to Raman scattering and AFMR disappear well below the Neel temperature, whose value was determined from neutron diffraction and magnetic susceptibility measurements.