Abstract
Four samples of the mixed spinel system CoxMn1-xAl2xFe2-2xO4 (x = 0.2, 0.4, 0.6, 0.8) were synthesized by ceramic sintering method. The magnetic ordering in the system has been investigated by neutron diffraction measurements in the temperature range 15-773 K. It appears that the system possesses a long-range ferrimagnetic ordering at x≤0.6 along with some randomly canted spin components, while at x = 0.8 a semi-spin glass behavior is observed. The latter composition exhibits three transitions: at temperatures larger than 100 K, there is formation of magnetic spin clusters showing super-paramagnetic type behavior before the true paramagnetic region is reached at about 200 K; a ferrimagnetic long-range ordering is observed in the temperature range 100-50 K; and finally below 50 K there is freezing of the magnetic spin clusters.
| Original language | English |
|---|---|
| Pages (from-to) | 9-17 |
| Number of pages | 9 |
| Journal | Journal of Alloys and Compounds |
| Volume | 298 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Feb 28 2000 |
Funding
The authors gratefully acknowledge the International Atomic Energy Agency for providing a fellowship at the Oak Ridge National Laboratory, USA to one of the authors (S.M. Yunus). The authors are also grateful to the Oak Ridge National Laboratory, USA managed by Lock-heed Martin Energy Research Corp. for the US Department of Energy under contract number DE-AC05-96OR22464. The authors wish to thank Dr. H.A. Mook and Dr. Bryan C. Chakoumakos of Oak Ridge National Laboratory for extending their cooperation for this work. The authors also like to thank Mr. M.A. Majid and Mr. M.A. Hakim of the Atomic Energy Center, Dhaka, Bangladesh for their indispensable help in the preparation of samples.