Investigation of the magnetic structure of the spinel compound ZnxCu1−xFeCrO4 by neutron diffraction

Studies of the magnetic ordering in the spinel system Zn0.4Co0.6AlxFe2−xO4 by neutron diffraction

“…The fluctuation of the diffuse signal with temperature indicates a freezing effect of the clusters. The results obtained in the present system are consistent with the results of other diluted spinel reported earlier [22,23,25,30].…”

“…Scattering from these short-range clusters has given rise to a huge diffuse signal that modifies the (1 1 1) Bragg diffraction peak. These features are compatible with a semi-spin glass nature [3,6,7,23,25,30]. Thus, the magnetic phase observed at x ≥ 0.75 can be termed as semi-spin-glass like structure, where the superposition of magnetic shortrange clusters over the magnetic long-range order (LRO) occurs, which is retained over the temperature range of investigation.…”

“…The diffuse signal broadens the (1 1 1) diffraction peak and this broadening effect is extended up to the position appropriate for the (2 0 0) reflection (2θ = 15.277 • ). The diffuse signal below the (1 1 1) peak in the diffraction patterns indicates the formation of magnetic spin clusters [6,7,[23][24][25]30] in all the composition under investigation. Scattering from these clusters has given rise to this diffuse signal which has broadened the (1 1 1) Bragg peak.…”

“…Among them the compound Zn x Ni 1−x FeCrO 4 was characterized as semispin-glass for x ≥ 0.6 [24], the system Zn x Cu 1−x FeCrO 4 was characterized as semi-spin-glass at x = 0.6 while it behaves as cluster spin-glass at x = 0.8 and at x = 0.75 [25]. The system Zn x Mg 0.75−x Cu 0.25 Fe 2 O 4 was reported to be a cluster spin-glass on the basis of the various features observed in our neutron diffraction patterns recorded as a function of temperature [6].…”

Cation distribution and crystallographic characterization of the quaternary spinel system Mg Co1−Cr Fe2−O4

“…From the consideration of electro-neutrality the obtained cation distribution suggests an oxidation state of three for both Fe and Cr while an oxidation state of two is consistent with both of Co and Mg. These atoms (Fe, Cr, Co and Mg) usually exist in such oxidation states in most of the spinel compounds [8,9,29,30]. The variation of the occupation factors of individual cations as a function of composition over the tetrahedral and octahedral sites are shown in Fig.…”