Magnetic properties of rare-earth-iron-boron permanent magnet materials

Abstract

Static magnetic measurements have been carried out on single crystals of Nd2Fe14B, Sm2Fe14B, and Y2Fe14B from 4.2 to 590 K. Values of K1 estimated from high field measurements at room temperature are 4.5, −12, and 1.1 MJ/m3 for Nd2Fe14B, Sm2Fe14B, and Y2Fe14B, respectively. Anisotropic behavior of the magnetization versus magnetic field curves in the basal plane has been observed for Sm2Fe14B, indicating large amplitude of the high order coefficients, K2 and K3. In Nd2Fe14B, the magnetization has been found to tilt from the c axis and simultaneously increase in magnitude. Average Fe moment is estimated to be 2.23 μB/Fe at 4.2 K from the saturation magnetization of Y2Fe14B.

MAGNET HIBRIDA BaFe12O19/Sm2Co17: SINTESIS DAN SIFAT KEMAGNETAN

“…Demikian juga dengan alloy magnetik berbasis logam tanah jarang Rare earth sistem RE-TM-B [1][2][3][4][5], Sm-Co [6][7][8] dan tidak terkecuali sistem keramik MO.6 Fe 2 O 3 M=Ba atau Sr [9][10]. Proses preparasi baik itu teknik konvensional seperti Powder Metallurgy [11] maupun teknik modern seperti Rapid Solidification [12] telah mampu menghasilkan sifat kemagnetan ekstrinsik yang mencapai 90-100 % nilai intrinsiknya.…”

Lorentz Force Flowmeter for Liquid Aluminum: Laboratory Experiments and Plant Tests

“…This force is directly proportional to the flow rate of the melt and can be measured exactly. Although the described phenomenon occurs whether the magnetic field is generated by a heavy electromagnet or by a lightweight permanent magnet, it is only because of the recent advent of powerful rare earth permanent magnets [12,13] and design tools for permanent magnet systems that a practical realization of this principle has now become possible. [5] The principle of an LFF can be understood better if one derives the basic scaling law of this device by invoking Ohm's law of a moving electrically conducting material in the following form:…”

“…At different rotation speeds, the probe immersed in the alloy gives linear dependences Eqs. [13] and [14] for corresponding components obtained by a probe orientation to the flow (Figure 3(b)). Calibration shows that the factors c v and c w are 7.48 9 10 3 (m/s V) and 3.35 9 10 3 (m/s V), respectively, if the potential difference is taken in volts and velocity components in m/s.…”

“…To define the volumetric flow rate, the signal Du ac passing through the voltmeter is applied to a computer in which, according to Eq. [13] and knowledge of the area of flow cross section, the flow rate q = v 9 A (where A denotes the area of flow cross section and v denotes mean velocity) is computed. For instance, the electrical signal Du ac = 10.1 9 10 À5 volts corresponds to an average maximum velocity of (v a ) max = 0.755 m/s.…”

Magnetization and Intrinsic Coercivity for τ-phase Mn54Al46/α-phase Fe65Co35Composite

“…The (BH) max for Nd 2 Fe 14 B are theoretically 64 MGOe [1] and experimentally 56 MGOe [2]. However, a low operation temperature and limited availability of rare-earth (RE) elements are potential barriers against the use of these RE element-based permanent magnets.…”