International Journal of Engineering & Technology IJET-IJENS Vol:14 No:01 88

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1 International Journal of Engineering & Technology IJET-IJENS Vol:14 No:01 88 Effect of Temperature On Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3) O 19 (x = 0.3, 0.7) Against Crystallite Size Characterization and Properties of Soft Magnetic Novizal 1, A. Manaf 2, Muhamad Hikam 3 1 Institute of Science and Technology National, Jakarta, ,3 Universitas of Indonesia, Depok, novizal23@yahoo.co.id Abstract-- In this paper, we report our investigation of influence of temperature on crystallite size characterization and properties of magnetic Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3)O 19 with x = 0.3, 0.7 alloy system prepared by a mechanical alloying process to promote soft magnetic properties. Index Term-- Particle size analysis, remanence, coercive field, the maximum density of magnetic energy INTRODUCTION Barium hexaferrite (BaFe 12 O 19 ) has been known as a permanent magnet material and is one of the most widely used materials in the field of magnetic recording media, which cannot easily be replaced with another magnet [1-3]. From a scientific stand point, and technology applications, barium hexaferrite present something special properties, such as: high remanence and coercivity, thermal stability, electrical and chemical [4,5]. The use of these materials as magnetic recording, microwave devices (microwave) and absorber [6] is in high demand so much effort is made to produce cation substitution into BaFe12O19 possible to improve magnetic properties. Divalent transition metal such as Co, Ti [7] and Mn [8] is often used as the equation of ionic radii and electron configurations. In this study barium hexaferrite substituted by ions using Mn, Ti and Sr. Manufacture of permanent magnets (barium hexaferrite) performed by the methode of ball mill, where the base material in milling powder together for 50 hours. During the milling process of interaction between the grains of the material that has been substituted very influent, especially for the smaller grain size. This is because the smaller the grain size the greater the interaction between the grains and affects the magnetic properties of the resulting material. Crystalline structure of Ba (1-x) Sr x Fe 11.4 Ti (0.3)Mn (0.3) O 19 analyzed using the data of X-Ray Diffraction (XRD). Magnetic properties of the material can be shown with the results of the data obtained from measurements with fermagraph methode. EXPERIMENT As a base material in the form of powder consisting of BaCO 3, SrCO 3, MnCO 3, TiO2 and Fe 2 O 3 stochiometri calculation for the composition of the material to be formed. All these ingredients are mixed using a ball mill with a composition ratio of 10:1. The material in milling for 50 hours with intervals every 10 hours made of powder for making particle measurements using a particle size analyzer (PSA). Completed the process of milling the material is still in powder form, in the calcination temperature 500 o C to eliminate CO 2, then in the form of cylindrical pellets using dies with pressure 70 kn. The heating process using the temperature variation furnishes 1000, 1100 and The results of XRD analysis of crystal size using Debye Scherer Equation: d = 0.9 x λ / β x cos d states where the crystal size, λ is the wavelength of X-rays, β is the FWHM (full width at half maximum at) from X-ray diffraction peaks are corrected, and is the Bragg angle. To analyze the magnetic properties of the material was measured by using fermagraph method. SEM result can be seen on distribution of the particles of the material. RESULTS AND DISCUSSION Figure 1 compares the average of particle size and crystallite size obtained from BaFe 12 O 19 based samples. The average particle size was found initially increased up to μm after mechanically milled for 20 hours, then start to decrease to a smaller size ~ 15 μm after 50 hrs milling time. Plot of particle size against the milling time showing a trend of further reduction in the mean particle sizes. It was also observed, the x-ray traces of dense pellet samples Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3) O 19 (x = 0.3, 0.7) after sintering at a temperature of 1000,1100 and 1200 o C showed broadened diffracted peaks pattern due and to fine crystallites in the samples after sintered at temperature 1100 o C in which values of mean crystallite size are compared also in Figure 2.

2 International Journal of Engineering & Technology IJET-IJENS Vol:14 No:01 89 X = 0.7 X = 0.3 Fig. 1. The particle size of BaFe 12O 19 and Ba (1-x) Sr xfe 11.4Ti (0.3) Mn (0.3)O 19 with x = 0.7 and x = 0.3. (a) (b) (c) Fig. 2. (a), (b), and (c) XRD pattern of Ba (1-x)Sr xfe 11.4Ti (0.3)Mn (0.3)O 19 with x = 0.3 and x = 0.7 at temperatures of 1200 o C, 1100 o C, and 1000 o C

3 International Journal of Engineering & Technology IJET-IJENS Vol:14 No:01 90 Fermagraph measurement results obtained from the data in Table I and II shows that the influence of temperature on the value of the material properties of magnetic very clear. At temperatures of 1200 o C shows the coercivity value of the material is very small and this leads to a value of magnetic properties of soft magnetic for x = 0.3 and x = 0.7. Table I Value of magnetic properties of materials BSHFTiMn 0307 Material Temperature Ms Mr Hc BSHFTiMn X= Fig. 4. Material shows Ba (1-x)Sr xfe 11.4Ti (0.3)Mn (0.3)O 19 at temperature variation with x = 0.7. Table I Value of magnetic properties of materials BSHFTiMn 0307 Material Temperature Ms Mr Hc BSHFTiMn X =

4 International Journal of Engineering & Technology IJET-IJENS Vol:14 No:01 91 Fig. 5. Material shows Ba (1-x)Sr xfe 11.4Ti (0.3)Mn (0.3)O 19 at temperature variation with x = 0.3. (a) (b) Fig. 6. Morphology of the surface of the material (a) Ba (1-x) Sr xfe 11.4Ti (0.3) Mn (0.3) O 19 and (b) Ba (0.7)Sr (0.3) Fe (11.4)Ti (0.3)Mn (0.3)O 19 with x = 0.3. and x = 0.7. The results of figure 6 look like the morphology of particles evenly distributed material formed with a size of about 1 µm, this phenomenon was difference with the particle size for the PSA method because the values are lm.this phenomena was difference with the particle size with PSA method because the value are µm. CONCLUSION Constituted components for alloy Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3) O 19 system have been characterized their particle and crystallite sizes by means of Particle Size Analyzer and XRD. Additional means also employing SEM for visual inspection to the morphology of particles. From the analysis results and discussion it is concluded that Mechanical Alloying followed by a sintering at C for alloy materials have promoted particles of nanocrystal with mean crystallite size of ~ 2 nm in Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3), x = 0.3 finer mean size of ~ 2 nm in Ba (1-x) Sr x Fe 11.4 Ti (0.3) Mn (0.3) x = 0.7 samples. Mean particle sizes for both gradually decreased towards a minimum value of a few microns. When milled particles for both materials are co-milled and sintered, the XRD identification showed that the material is roaming a mixture, no decomposition or transformation. That s why the internal structure formed alloy of a one-phase mixture consisted of stable phases of respective constituted alloy materials. Size material substituted with Sr, Ti, and Mn in the process of particle size reduction milling experience to micro size (1 µm). The material is heated to 1100, 1200oC has a very small value of coercivity and can be promoted as soft magnetic materials ACKNOWLEDGMENT The author would like to thank LPPM ISTN and UI Physics Laboratory for the implementation progress of this research was funded by LPPM ISTN.

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