Copper ferrite

A number of ferrites have been subjected to shock modification and studied with x-ray diffraction as well as static magnetization and Mossbauer spectroscopy [87V01], Studies were carried out on cobalt, nickel, and copper ferrites as well as magnetite (iron ferrite). 

Person 1 Calculate the net magnetic moment per unit cell for copper ferrite. Remember that there is more than one formula unit (CuFe204) per unit cell in the inverse spinel structure. 

Person 2 Calculate the saturation magnetization, Ms, for copper ferrite, which has a lattice parameter of a = 0.838 nm. 

Encinas-BachUlerP, Tascon-GarciaML, Vazquez-Barbado MD, Sanchez-Batanero P (1994) Electroanalytical study of copper and iron compounds in the solid state apphcation to copper ferrite characterization. J Electroanal Chem 367 99-108. 

Copper ferrites have been included in the model, but have as yet not been found to be equilibrium controls on copper or iron solubility. The calculated activity products for the two minerals, cuprous ferrite and cupric ferrite, are characteristically several orders of magnitude oversaturated when compared to their respective equilibrium constants in a wide variety of surface waters. 

A similar investigation of carbon dioxide adsorption on reduced nickel leads to the conclusion that the best agreement is obtained under the assumption that n is 3, i.e., that the CO2 molecule completely dissociates on adsorption (45). On the other hand, agreement is obtained for carbon dioxide adsorption on copper ferrite for w = 2. On ferric oxide the assumption of n = 1, tentatively suggested by the nearly direct proportionality... 

Fig. 8. Adsorption isotherms of CO2 on reduced nickel (T = 200°C., Ae = 22 kcal./mole), copper ferrite (T = 300°C., Ae = 31 kcal./mole), and ferric oxide (T = 300°C., Ae = 29.5 kcal./mole).

Kwan and Fujita (7fi) investigated the adsorption of carbon dioxide on a copper ferrite catalyst of the composition CuO-Fe203, prepared by the usual precipitation method and ignited at 500°C. in vacuo for about one month. Special precautions were made in the adsorption studies for attaining true adsorption equilibria. The adsorption isotherm for the low... 

Figure 1. Experimental setup for water splitting with copper ferrite...

Figure 2 shows the XRD pattern of the copper ferrite prepared by co-precipitation. The diffraction peaks in the scanning range include 112, 103,211, 220, 224 and 321 and the strongest peak appears at around 35°, these correspond to the structure characteristics of the spinel compounds, the strongest peak corresponds the 211 crystal surface. There is no other peak in the spectrum, indicating that the product is pure compound. The crystalline data were shown in Table 1. 

The formation ofthe spinel consists of two steps. Firstly, the hydroxide formed in co-precipitation occurs dehydration reaction to form oxides, then tire oxides was calcined to form copper ferrite with spinel structure. If the calcinations temperature is not high enough or tlie time is not long enough, the phase transformation could not be finished. Therefore, only the temperature exceeds 800°C, it is possible to form homogenous spinel type CuFe2O4 furthermore, the longer calcinations process is beneficial to the formation of pure spinel type ferrites. 

Figure 4. Tliermocgravimetric measurements of copper ferrite at different atmosphere (a in air b in 2 crucible AI,(), temperature 100 to 1 IOO°C at 30°C/min)...

Several alternatives to the sulfiir-iodine process and steam electrolysis are being considered. Thermo-electrochemical cycles at various stages of development are being studied, including two hybrid sulfur-based cycles, the copper-chloride cycle, the magnesium-chloride cycle, the copper ferrite cycle,. Screening tools have been developed to rapidly assess less mature thermo-electrochemical cycles to help decide whether further research is warranted. 

G. Matei, I. Jitaru, E. Andronescu and A. Novae, Preparation of Copper Ferrite by Reaction of Various Precursors with the Molten NaN03-KN03 Medium, in Advances in Molten Salts. From Stmctural Aspects to Waste Processing, ed M. Gaunr-Escard (Begell House, NY, 1999) pp. 242-248. 

Metselaar, R. Huyberts, M. A. H. (1973). The stoichiometry and defect structure of yttrium iron garnet and the nature of the centres active in the photomagnetic effect. Journal of Physics and Chemistry of Solids, 34,2257-63. Miyahara, S. Ohnishi, H. (1956). Cation arrangement and magnetic properties of copper ferrite-chromite series. Journal of the Physical Society, Japan, 11, 1296-7. 

Prince, E. Treating, R. G. (1956). The structure of tetragonal copper ferrite. 

It will, of course, be understood that this explanation of thermal deactivation is by no means the only deactivation process which can occur. Morris and Selwood found that nickel supported on magnesia could be thermally deactivated with no recession of the Curie point. Nevertheless, the method seems to be a powerful one, which might be applied to other ferromagnetic metals, and to ferromagnetic oxides and ferrites such as copper ferrite undergoing isomorphous replacement of copper by zinc, as described by Snoek (44). 

Zal] Zalazinskii, A.G., Balakirev, V.F., Chufarov, G.I., Thermodynamic Activity of Components of a Binary Sohd Solution Copper Ferrite (Cuo.5Fe2.504)i c(Fe304) , (in Russian) in Khim. Tekhnol. Oksid. Magnit. Mater. , Akad. Nauk SSSR, Volgograd, 3, 100-102 (1977) (Experimental, Thermodyn., 5)... 

Dhu] D Huysser, A.D., Lerebours-Hannoyer, B., Lenglet, M., Bonnelle, J.P., Spectroscopic, Photoelectron and X-Ray Investigations of Cu(+) and Cu(2+) Copper Ions in Copper Ferrites (in French), J. Solid State Chem., 39, 246-256 (1981) (Crys. Stmeture, Optical Prop., Experimental, 43)... 

Brel] Brezeanu, M., Patron, L., Contescu, A., Structure and Properties of Copper Ferrite. I. General Considerations (in Romanian), Rev. Chim. (Bucharest), 40(5), 404-407 (1989) (Crys. Structure, Experimental, Magn. Prop., 36)... 

Tan] Tang, X., Xia, M.A., Goodenough, J.B., Copper Ferrite Revisited , J. Solid State Chem., 79 (2), 250-262 (1989) (Crys. Structure, Experimental, Theory, 26)... 

Goyl] Goya, G.F., Rechenberg, H.R., Jiang, J.Z., Structural and Magnetic Properties of Ball Milled Copper Ferrite , J. Appl. Phys., 84(2), 1101—1108 (1998) (Crys. Stracture, Experimental, Magn. Prop., Electronic Stracture, 33)... 

Copper zinc iron oxide, 98.5% trace metal basis (zinc copper ferrite, copper zinc ferrite) ]66402-68-4] M 416.3 (CuZnFe404), d 4 5.5. It is a nano powder with particle size <100nm (BET). The actual particle size is <50nm (XRD) and is commercially available. 

The sonochemical method has been applied to obtain nanoparticles of magnets such as Fe, Fc304, Fc203, cobalt ferrite and copper ferrite in Refs [259, 260, 267]. If the sonication occurs in the presence of oxygen, the oxide phases are obtained [267, 268]. In the case of Fc203, the sonolysis results in amorphous nanopowder,... 

Copper ferrite CuFejO, Spinel type, cubic H11, cF56 (Z = 8) Fd3m 0.17 455... 

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