Structure and magnetic properties of high coercive NdFeB films with a perpendicular anisotropy

Abstract

Relatively good hard magnetic properties obtained from Nd2Fe14B films prepared by the rf sputtering technique were investigated in terms of the microstructural development. Although as-deposited films on Mo substrates deposited at substrate temperatures (Ts) of 365 °C were amorphous with the dispersion of nanocrystalline NdO particles, columnar grains of Nd2Fe14B phase with the c-axis perpendicular to the film plane developed after annealing at 650 °C at an optimized heating rate. Nd2Fe14B grain size was about 400 nm in average and NdO particles of about 10 nm were dispersed within the grains and along the grain boundaries. These films exhibited good perpendicular hard magnetic properties of Hci=1356 kA/m and (BH)MAX∼216 kJ/m3.

Effect of annealing on magnetic properties of Nd-Fe-B thin films prepared by ECR ion beam sputtering method

“…The magnetic properties were measured using a vibrating sample magnetometer (VSM) with a maximum field of 20 kOe. the crystallization between the crystallization temperature and sputtering temperature and sputtering temperature [3,5,6]. Even with a deposition temperature below the temperature required to crystallize…”

Thin films of NdFeB deposited by PLD technique

“…Changing of deposition parameters (such as temperature, composition and especially the thickness) it is possible to control the phase formation, texture and grain sizes, and thus to optimize the coercivity and magnetic texture. The Nd 2 Fe 14 B phase providing the desired intrinsic magnetic properties has a tetragonal unit cell (a = 8.805 Å , c = 12.203 Å ) and it comprises 68 atoms [16,17]. Unfortunately, as the domains size limits in thin films for recording media is around 7 nm and the Nd 2 Fe 14 B has a typical domain size of a larger value (20-100 nm) [3], this excludes it for such applications, www.elsevier.com/locate/apsusc Applied Surface Science 253 (2007) 8192-8196 but makes it a good candidate for the developing of microelectromagnetic devices.…”

Effective anisotropy field in anisotropic nanostructured ferromagnetic materials

“…Recently, the fabrication of the nanostructured permanent magnets with anisotropic growth of grains, especially, PrCo 5 -type bulk magnets [12,13] and Nd 2 Fe 14 B-type thin films [28][29][30][31], has increasingly come into the focus of interest. However, understanding effects of intergrain exchange coupling on the textured ferromagnets with nanocrystalline structures is still rudimentary [32].…”