Computer Aided X-Ray Diffraction Intensity Analysis for Spinels: Hands-On Computing Experience
The mineral having chemical compositional formula MgAl2O4 is called “spinel". The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has a fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). The X-ray diffraction (XRD) intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. This leads to the method of determination of distribution of cations in the spinel oxides through XRD intensity analysis. The computer program for XRD intensity analysis has been developed in C language and also tested for the real experimental situation by synthesizing the spinel ferrite materials Mg0.6Zn0.4AlxFe2- xO4 and characterized them by X-ray diffractometry. The compositions of Mg0.6Zn0.4AlxFe2-xO4(x = 0.0 to 0.6) ferrites have been prepared by ceramic method and powder X-ray diffraction patterns were recorded. Thus, the authenticity of the program is checked by comparing the theoretically calculated data using computer simulation with the experimental ones. Further, the deduced cation distributions were used to fit the magnetization data using Localized canting of spins approach to explain the “recovery" of collinear spin structure due to Al3+ - substitution in Mg-Zn ferrites which is the case if A-site magnetic dilution and non-collinear spin structure. Since the distribution of cations in the spinel ferrites plays a very important role with regard to their electrical and magnetic properties, it is essential to determine the cation distribution in spinel lattice.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1333917Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3448
 L. Neel, "Propriétées magnétiques des ferrites; Férrimagnétisme et antiferromagnétisme," Annales de Physique, Paris, vol. 3, pp. 137-198, 1948.
 Y. Yafet and C. Kittel, "Antiferromagnetic arrangements in ferrites,"Physical Review, vol. 87, no. 2, pp. 290-294, March 1952.
 A. Rosencwaig, "Localized canting model for substituted ferrimagnets. I. Singly substituted YIG systems," Can. J. Physics, vol.48, pp. 2857- 2867, Dec. 1970.
 A. Rosencwaig, "Localized canting model for substituted ferrimagnets. II. Doubly substituted YIG systems," Can. J. Physics, 48, pp. 2868- 2876, Dec. 1970.
 C. E. Patton and Yi-hua Liu, "Localized canting models for substituted magnetic oxides," J. Phys. C: Solid State Phys., vol. 16, pp.5995-6010, Nov. 1983.
 B.D. Cullity, Elements of X-ray diffraction II Edition, Addision-Wesley Pub. Co., 1978, ch. 4.
 S.K. Chatterjee, "X-ray diffraction- its theory and applications," PHI, 1999, ch. 3.
 W. H. Bragg, "The structure of the spinel group of crystals," Phil. Mag., vol. 30, pp. 305-315, Aug. 1915.
 S. Krupicka and P. Novak, "Ferromagnetic materials," Vol. 3 North- Holand Publishing Co. New York, 1982, ch. 4
 K. E. Sickafus, J. M. Wills and N. W. Grimes, "Structure of Spinel," J. Am.Ceram. Soc., vol. 82, no. 12, pp. 3279-3292, Dec. 1999.
 K.J. Standly, "Oxide Magnetic Materials," Clerenden press, Oxford, 1962, ch. 2.
 C. Radhakrishnamurty, S.D. Likhite and N.P. Sastry, "Low temperature magnetic hysteresis of fine particle aggregates occurring in some natural samples," Philos. Mag, vol. 23, pp. 503-507, Feb. 1971.
 S.D. Likhite and C. Radhakrishnamurty, "Initial Susceptibility and Constricted Rayleigh Loops of some Basalts,"Curr. Sci., vol. 35, pp. 534-536, Nov. 1966.
 H. Ohnishi, T.Teranishi, "Crystal Distortion in Copper Ferrite-Chromite Series," J. Phys. Soc. Jpn., vol. 16, pp.35-43, Jan. 1961.
 A. Miller, "Distribution of Cations in Spinels" J. Appl Phys, vol. 30, pp. S24-S25, Apr. 1959.
 H. H. Joshi and R. G. Kulkareni, "Susceptibility, magnetization and Mossbauer studies of the Mg-Zn ferrite system," J. Materials Sci. vol. 21, no. 6, pp. 2138-2142, June 1986.
 B.D. Cullity, "Introduction to magnetic materials," Addison Wesley, 1972, ch. 4.