Anisotropic Nd–Fe–B thin-film magnets for milli-size motor

Abstract

Efforts were made to obtain anisotropic thin-film magnets at low substrate temperature. This is an important criterion for practical applications such as to build motors. The influence of substrate materials as well as film thickness on the c-axis orientation were studied. It has been shown that thin-film magnets with the easy axis of magnetization normal to the film plane could be deposited at a substrate temperature of around 450 °C by choosing the composition near the line from Nd13Fe76B11 to Nd13Fe70B17 in the ternary phase diagram. It was found that the anisotropic film magnets could be also deposited on the metallic substrate. The c-axis orientation tended to be isotropic with an increase in film thickness. The obtained results were used to fabricate a milli-size motor by depositing 20-μm-thick Nd–Fe–B films on a silicon steel disk substrate of 5-mm diam. The milli-size motor exhibited a torque of 0.8 g mm at a rotational speed of 3000 rpm.

Pulsed Laser Deposition of permanent magnetic Nd 2 Fe 14 B thin films

“…Torque measurements show indeed the presence of such an anisotropy along axes which are, although varying from film to film, always within 10" from the film normal. It has been observed earlier [4] in sputtered films that a close correlation exists between the degree of c-axis orientation and the occurrence of a magnetic behaviour similar to the one shown in Fig. 2.…”

A method of preparing anisotropic Nd–Fe–B film magnets by pulsed laser deposition

“…1 In the sputtering method, Nd-Fe-B film magnets thicker than 10 m have been reported. [2][3][4][5][6] It has also confirmed that a substrate heating method is effective in obtaining anisotropic sputtered Nd-Fe-B samples. [2][3][4][5][6] For example, Uehara reported superior magnetic properties of a Nd-Fe-B / Ta multilayered thick film.…”

Optical Properties of Complex Oxide Thin Films Obtained by Pulsed Laser Deposition

“…NdFeB thin films were deposited by various methods, e.g., magnetron sputtering, molecular beam epitaxy (MBE), and PLD [22][23][24][25].…”