Neutron diffraction and other studies of magnetic ordering in phases based on Cr 2O 3, V 2O 3 and Ti 2O 3
Abstract
Solid solutions in the Cr 2O 3V 2O 3 and Cr 2O 3Ti 2O 3 systems have been examined by neutron diffraction, X-ray diffraction, electron spin resonance and magnetic susceptibility methods. In (Cr xV 1- x) 2O 3 the low temperature monoclinic V 2O 3 phase was found to extend from x = 0 to x = 0.5. Long-range order in this phase disappears gradually as x increases. For 0.4 < x < 1.0 two kinds of antiferromagnetic order were observed both based on the Cr 2O 3 magnetic structure. In (Cr xTi 1- x) 2O 3 only the Cr 2O 3-type antiferromagnetic structure was found with the Ti 3+ ions acting as a simple diluent. The electron spin resonance signal from Cr 3+ in (Cr xV 1- x) 2O 3 is found to be quenched by dipolar interaction with V 3+; however, that for Ti 3+ in (Cr xTi 1- x) 2O 3 is observable above and below the temperature for Cr 3+ spin ordering. The lattice parameters for the (Cr xV 1- x) 2O 3 system show a sharp discontinuity in the region 0 < x < 0.02. From the data outside this region an ionic radius for paramagnetic V 3+ of 0.645 Å is derived. It is found that, for many corundum-structure magnetic systems, ordering is independent of the spin state of the diluent atoms.
- Publication:
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Journal of Solid State Chemistry France
- Pub Date:
- May 1972
- DOI:
- 10.1016/0022-4596(72)90155-7
- Bibcode:
- 1972JSSCh...4..400R