Femtosecond laser synthesis of composite magnetic nanoparticles based on iron in liquid
Anton S. Chernikov, Dmitriy A. Kochuev, Maria A. Dzus, Ruslan V. Chkalov, Elena I. Shingareva, Khorkov K.S.; Vladimir State University, Vladimir, Russia
Abstract
The Yb:KGW femtosecond laser system (Avesta, Russia) was used as a radiation source in experiments on laser ablation synthesis. The radiation wavelength was 1030 nm, the maximum energy in a pulse was 150 µJ, the pulse duration was 280 fs, and the pulse repetition frequency was 10 kHz. Scanning with a laser beam over the target surface during laser ablation and fragmentation in a liquid medium was carried out using an X-Y galvanoscanner, focusing was carried out using an F-theta lens with an operating distance of 200 mm. Deionized water was used as a liquid medium. A high purity iron target (99.95%) (diameter 25 mm, thickness 3 mm) was used in the experiments. Before the start of the laser ablation synthesis process, the target was weighed, after which it was placed at the bottom of a cuvette filled with deionized water (15 ml). The cuvette was installed in the processing area, and then the focus position was adjusted using a vertical translator. The height of the liquid above the target during laser ablation was about 5 mm. The laser processing area was a circle with a diameter of 20 mm, the scan track filling density was 100 lines/mm, the scanning speed was 100 mm/s, the pulse energy was 50 ΜJ, and the process duration was 10 minutes. To select nanoparticles with magnetic properties, the obtained colloidal solutions were subjected to a magnetic separation step. Magnetic separation of nanoparticles was carried out using a permanent magnet with a maximum magnetic field of 3,000 Gauss. The magnet was located at the side wall of a tube with a colloidal solution, after 5 minutes the magnet smoothly shifted from the wall to the bottom of the tube, thereby transferring magnetic nanoparticles, then the filler fluid was removed, leaving the minimum possible volume of liquid medium in the tube. The same volume of liquid was added to the remaining nanoparticles at the bottom, which was previously repeated three times. The share of magnetic woofers from the total mass of the removed material was ~ 45%.
The work was carried out within the framework of the state assignment in the field of scientific activity of the Ministry of Science and Higher Education of the Russian Federation (topic FZUN-2024-0019, state assignment of the All-Russian State University).
Speaker
Kirill Khorkov
Vladimir State University
Russia
Discussion
Ask question
