Enhancement in coercivity of Pulsed Laser Deposition-fabricated Fe-Pt thick film magnets by reducing droplets

Abstract

A high-speed Pulsed Laser Deposition method with the deposition rate of several ten microns per hour followed by a post-annealing process enabled us to obtain isotropic Fe-Pt thick film magnets with the L1 0 order phase. In the study, we investigated the relationship between droplets and coercivity of the post-annealing films. It was found that the reduction in the numbers of droplets enabled us to increase the coercivity although the average deposition rate decreased from 40 to 15 lm per hour. In the samples with Ra less than 0.5 lm, the coercivity exceeded 450 kA/m at the annealing temperature of 673 K. A SEM-EDX analysis of droplets revealed that they tended to have iron-rich or platinum-rich compositions compared with the average one of Fe 50 Pt 50 .

Effect of Preparation Condition on Magnetic Properties of ${\rm Nd-Fe-B}/\alpha-{\rm Fe}$ Multi-Layered Thick Film-Magnets Prepared by PLD Method

“…4, and would prevent a stable movement of particles emitted from the target to the substrate. In addition, it has been found that the compositions of droplets differ from that of non-droplet part of Sm-Fe [16] and Fe-Pt [17] films prepared by the PLD method. Therefore, the unstable movement of the particles is possibly responsible to the scattering of the film composition and magnetic properties.…”

“…During the ablation, the target was rotated at the speed of 3.3-13 rpm and a multi-layered film was deposited on a Ta substrate. The deposited films were [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] in thickness. The layer numbers synthesized in one hour are deduced from the above rotation speeds as 396 and 1560, respectively.…”