Dear Respected RG experts
Why cation distribution in spinel ferrites are dependent on preparation conditions?
What are the possible reasons?
Your kind views and suggestions are most welcome
With thanks
Basically, preparation conditions can influence cation distribution mainly because of: (i) Temperature. (ii) Oxidation state of a transition-metal cation.(iii) Particle size of the obtained spinel. See:
(i) Because of the entropic contribution, increasing temperature tends to favour an increasing randomization of cation distribution.
(ii) Often, heating to a high temperature for a long time can lead to a change in the oxidation state of a transition-metal cation; unless the heating is performed under a carefully controlled atmosphere.
(iii) Very small spinel particles (having a size in the nano-metre range) often show a cation distribution (and cation oxidation state) which significantly deviates from that expected at equilibrium.
Hope that helps.
Best regards,
Carlos
Thank you so much Dr Carlos for the kind response and the elegant answer. Sir, you have summarize all the important points which affects the cation distribution. I have also observed the important changes in the properties due to the changes in processing parameters which can be attributed to the cation distributions. In fact, I am searching for some relevant literatures for these dependency. So, I will be very grateful if you provide some relevant literatures, espicially for factor one and three.
With best regards
Chitra
See, for instance, articles 1 to 3 below (and references therein):
1) Temperature dependence of cation distribution and oxidation state in magnetic Mn-Fe ferrite nanocrystals.
Z. John Zhang, et al.
J. Am. Chem. Soc. 120(1998)1800-1804.
2) The temperature dependence of the cation distribution in synthetic hercynite (FeAl2O4) from in-situ neutron structure refinements.
R.J. Harrison et al.
American Mineralogist 83(1998)1092-1099.
3) Particle size dependent cation distribution in lithium ferrite spinel LiFe5O8.
I. Bergmann et al.
Rev. Adv. Mater. Sci. 18(2008)375-378.
Best wishes,
Carlos
Thank you so much Sir.
I will go through these important articles. In fact, I think I have already gone through some of your nice contributions in this field. It is really very nice to meet you sir and having valuable suggestions directly.
Thanks a lot again for the kind response and suggestions.
With best regards
Chitra
ARTICLES YOU MAY BE INTERESTED IN,
If you are working in the feild of Spinel Ferrites
https://www.researchgate.net/publication/329554668_Multilevel_resistive_and_magnetization_switching_in_CuCoFe2O4Pt_device_Coexistence_of_ionic_and_metallic_conducting_filaments
https://www.researchgate.net/publication/323141836_Electroforming_Free_Controlled_Bipolar_Resistive_Switching_in_AlCoFe2O4FTO_device_with_Self-Compliance_Effect
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity