Ferrite-based material as a permanent magnet for components of electrical generators

Abstract

A permanent magnet based on ferrite for use as components of electrical generators has been fabricated by two different methods: solid–solid mixing and cooprecipitation. The conventional solid–solid mixing method uses Fe 2 O 3 and BaCO 3 as starting materials with mole ratio n=BaO:Fe 2 O 3=1: 6. The mixture is calcinated at 1100 °C and two crystal structures, BaOFe 2 O 3 and BaFe 12 O 19, were obtained with particle size of about 0.5–1.5 μm. Sintering at 1100 °C was followed by a magnetization process. Measurements give the following physical parameter values: remanence, Br=0.0792 T; magnetic saturation, Bs=1.21 T; coersivity, Hc=44.7 kA m -1; density 3.43 g cm -3 and porosity 9.16%. On the other hand, the cooprecipitation method uses FeCl 3 and BaCl 2 solution with mole ratio n=BaCl 2:FeCl 3=1:6. After the calcination at 900 °C and higher temperatures a single crystal structure of BaO·6Fe 2 O 3 is formed with particle size of about 30–60 nm. The optimum sintering temperature for the formation of this single phase crystal structure is 1050 °C. The physical parameters of the final product have the following values: Br=0.2673 T; Bs=1.42 T; Hc=89.4 kA m -1; density 4.34 g cm -3 and porosity 3.36%.

Tingkat Pengetahuan Siswa Kelas Xi Terhadap Penggunaan Antasida Di Sman 2 Banguntapan Bantul

“…Beberapa survei menunjukkan bahwa gastritis paling sering menyerang usia produktif, yaitu pelajar. Menurut penelitian yang dilakukan oleh Sebayang (2011) penyakit maag semakin meningkat pada pelajar di akhir usia belasan dengan jumlah penderita gastritis sebanyak 88 responden, mayoritas berusia antara 18-23 tahun atau 74 orang (84,1%). Siswa SMAN 2 Banguntapan kelas XI mayoritas masih berusia 17-18 tahun serta memiliki aktivitas yang padat dan kemungkinan tidak terlalu memperhatikan pola makan.…”

Preparation and Characterization of Isostructural Na2MoO4 and Na2WO4 and a Study of the Composition of Their Mixed System

“…However, in some cases, it is possible to prepare them using other “soft” methods at low temperature [ 16 ]. Among them, one of the most significant is the co-precipitation route [ 17 , 18 ]. Briefly, the principle of this method is to prepare liquid solutions of the parent compounds at low temperature, mix them in the desired ratios, and then add a suitable precipitating agent.…”

The Effect of Variation in the Number of Pole and Air Gap on Torque Density on Radial Magnetic Spur Gear with Magnetic Block

“…It is known that the greater the residual induction (Br) and coercivity (Hc), the better the properties of the object are to maintain the external magnetic field. However, until now, there are only four types of magnets that are commonly used as permanent magnet materials, namely AlNiCo [11], Feritte [12], SmCo5 [13], and the most recently discovered, NdFeB [14]. The properties of these materials is shown in Table 1.…”