Electron back scattered diffraction study of SmCo magnets

Crystallographic orientation-dependent magnetic properties of a PrCo5permanent magnet prepared by hot deformation

“…Furthermore, a strong c-axis orientation texture generally indicates an intimate connection between the {0001} planes (perpendicular to the c-axes) of the PrCo 5 crystals. In particular, PrCo 5 has a c/a value of 0.798 and the [0001] hexagonal c-axis of the unit cell is the desirable texture axis, 11 presenting a favorable condition for the occurrence of the coincidence site lattice (CSL) boundary, Σ13a. 12 Here, the Σ value represents the reciprocal density of coinciding sites and the symmetrical configuration of the boundary planes.…”

Orientation textures of grains and boundary planes in a hot deformed SmCo5 permanent magnet

“…Since its discovery in 1967, 1 the permanent magnet intermetallic compound SmCo 5 has been widely studied both experimentally 2 and theoretically. 3 As a promising candidate for thin film recording media, 4,5 the performances of the SmCo 5 magnet are determined by its crystallographic features to a large extent, which can be summarized as the following aspects: (1) in permanent magnets with uniaxial magnetic anisotropy, the saturation magnetization and the remanence are determined by the grain orientation texture, 6 which provides the information about grain alignment and helps to measure the efficiency in acquiring remanent magnetization; 7 (2) the SmCo 5 magnet has a high magnetocrystalline anisotropy constant of 1.1 × 10 8 erg cm −3 , 4 and the magnetocrystalline anisotropy parameter has a close relation to both magnetic hysteresis characteristics 2 and thermal fluctuation of the magnetic moment, 8 and particularly, locations with low magnetocrystalline anisotropy are often concentrated near grain boundaries; 9 (3) improving the corrosion resistance of the SmCo 5 magnet is an important issue, 5 and corrosion resistance has been demonstrated to be closely correlated to the distribution features of grain boundaries on a statistical basis, namely the "grain boundary character distribution (GBCD)". 10 In brief, characterizing the crystallographic textures of the SmCo 5 magnet has major significance.…”

“…3) and the [0001] hexagonal axis of the unit cell is the desirable texture axis, 6 which leads to the high frequency occurrence of a coincidence site lattice (CSL) boundary namely the Σ13a grain boundary; 11 here, the Σ value represents the reciprocal density of coinciding sites and the symmetrical configuration of boundary planes, and the basic crystallographic feature of the Σ13a boundary can be described as a 27.796°rotation about the [0001] axis (abbreviated as 27.796°/[0001]). Therefore, the crystallographic textures of the SmCo 5 magnet should include the orientation textures of both SmCo 5 grains and SmCo 5 /SmCo 5 grain boundary planes.…”

Electron back scattered diffraction characterization of Sm(CoFeCuZr)z magnets

“…Until now, only transmission electron microscopy (TEM) had been used. 4. Permanent magnets based on the Sm 2 Co 17 phase present high intrinsic coercivities at high temperatures (up to 1 T at 500 C) which make them suitable for high technology applications.…”

“…4 EBSD-orientation imaging microscopy (OIM) scans and EDS measurements were performed in a FEI Quanta 200 TSL/ SEM with a tungsten filament. 4 EBSD-orientation imaging microscopy (OIM) scans and EDS measurements were performed in a FEI Quanta 200 TSL/ SEM with a tungsten filament.…”