Studies on interaction of electromagnetic waves with barium hexaferrite ceramics

Gürkan, Nurdan
M-type barium hexaferrite powders doped with titanium and/or cobalt have been synthesized according to the stochiometric formulations BaFe(12 (4/3)x)TixO19, BaFe12-xCoxO19 , BaFe12-2xTixCoxO19 (x varying from 0 to 1.5 with an increment of 0.5) by the mixed oxide approach. The powders were used to manufacture small ceramic tiles by sintering each composition at 1250 °C with soaking times ranging from 1 to 16 hours. XRD work revealed formation of the magnetoplumbite crystal structure in all ceramics. The variations in processing parameters led to differences in microstructure and various dielectric and magnetic properties of the ceramic tiles. The interaction of the ceramics with electromagnetic waves was characterized by using a vector network analyzer in the X and Ku bands. The results revealed that, undoped barium hexaferrite ceramics and those doped with low titanium exhibited good microwave absorption properties.


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Örs, Taylan; Öztürk, Tayfur; Department of Metallurgical and Materials Engineering (2008)
In this study ferroboron (Fe - 14 at %B) was synthesized in crystalline form (Fe + Fe2B) via electrodeoxidation. For this purpose, Fe2O3 and H3BO3 were mixed in suitable proportions via spex mill. The powder was cold pressed and sintered at 900 °C yielding a two phase structure Fe3BO6 and Fe2O3. The sintered pellets were electro-deoxidized in CaCl2 by applying 3.1 Volts at 850°C for 12 hours. This yielded Fe and Fe2B in proportions slightly deviating from the target composition. The chemical pathway of redu...
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In this paper an artificial neural network (ANN) has been developed to compute the magnetization of the pure and La-doped barium ferrite powders synthesized in ammonium nitrate melt. The input parameters were: the Fe/Ba ratio, La content, sintering temperature, HCl washing and applied magnetic field. A total of 8284 input data set from currently measured 35 different samples with different Fe/Ba ratios, La contents and washed or not washed in HCl were available. These data were used in the training set for ...
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Citation Formats
N. Gürkan, “Studies on interaction of electromagnetic waves with barium hexaferrite ceramics,” M.S. - Master of Science, Middle East Technical University, 2008.