EFEK HIGH ENERGY MILLING TERHADAP KOERSIVITAS MAGNET INTRINSIK BaO.6Fe2O3
Keywords:
Barium Heksaferit, Barium Hexaferrite, High Energy Milling, Koersivitas Magnet, Magnetic CoersivityAbstract
EFEK HIGH ENERGY MILLING TERHADAP KOERSIVITAS MAGNET INTRINSIK BaO.6Fe2O3. Studi mengenai sifat magnet serbuk bahan BaO.6Fe2O3 akibat proses penghalusan menggunakan high-energy milling yang diikuti oleh perlakuan annealing pada suhu 400 ºC, 600 ºC, 800 ºC, 1000 ºC dan 1100 ºC telah dilakukan. Penurunan sifat magnet bahan setelah di milling selama 30 jam disebabkan telah terjadi deformasi kristal bahan. Proses annealing terhadap serbuk hasil milling di bawah suhu 800 ºC selama 3 jam belum dapat mengembalikan sistem fasa sepenuhnya. Setelah suhu anneal ditingkatkan hingga 1000 ºC, fasa BaO.6Fe2O3 tumbuh kembali dengan koersivitas intrinsik meningkat hingga Hci = 4,4 kOe, dibandingkan dengan koersivitas serbuk magnet sebelum proses milling Hci yang hanya 1,7 kOe. Peningkatan koersivitas intrinsik ini sangat terkait dengan ukuran partikel yang jauh lebih halus dibandingkan dengan yang tidak di milling. Annealing pada suhu 1100ºC, menunjukkan terjadi penurunan kembali koersivitas intrinsik Hci = 3,7 kOe, ini diperkirakan akibat adanya pertumbuhan kristalit.
ABSTRACT
HIGH ENERGY MILLING EFFECT ON INTRINSIC MAGNETIC COERSIVITY OF BaO.6Fe2O3. The magnetic properties of BaO.6Fe2O3 fine powder milled by high-energy milling followed through annealing on 400ºC , 600ºC , 800ºC , 1000ºC and 1100ºC have been studied. The decreasing of magnetic properties for 30 hours milled samples is due to the deformation of crystalline materials. Annealing process of milled powders under 800ºC for 3 hours could not recover the phase system completely. After annealing temperature was increased to 1000ºC the BaO.6Fe2O3 has been growth with the intrinsic coersivity increased to the Hci = 4.4 kOe, comparing to the powder magnet before milling that the Hci only 1.7 kOe. These coersivity enhancement was closed related to the particle sizes which are very finer compare to the particles sizes of unmilling powder. At annealing temperature 1100ºC, show that intrinsic coersivity decreased again to the Hci = 3.7 kOe, it may due to the crystal growth.
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