Influence of high anisotropy phase on the properties of hard–soft magnetic nanocomposite powders obtained by mechanical milling

ABSTRACT

In materials with a good degree of magnetic interphase exchange coupling one has to consider both the extrinsic (microstructure) and intrinsic parameters (magnetisation, anisotropy, etc.) of the composite. This study investigates the feasibility of tuning the interphase exchange coupling condition by varying the anisotropy through the choice of the hard magnetic phase. The studied samples were produced by milling the hard magnetic phase along with 20 wt-% α-Fe powder for 6 h and subsequent annealing. The structure of the annealed powders was studied through X-ray diffraction and the magnetic properties of the nanocomposites were studied from demagnetisation curves and vs H plots in applied fields up to ±10 T.

KEYWORDS:

• Mechanical milling
• hard–soft magnetic nanocomposite
• permanent magnet
• exchange coupling

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

R. Hirian (1988) got an Engineer diploma, Masters degree (solid state physics) and PhD (2018) from Babeş-Bolyai University, Cluj-Napoca, Faculty of Physics. He is currently a post-doc at the same institution. His specialty is materials science, with a focus on magnetic materials (synthesis and characterization).

A. Bolinger got a Bachelors Diploma in physics (2016) and is a Masters Student (solid state physics) at Babeş-Bolyai University.

O. Isnard (1965) got an Engineer diploma from technical University of Grenoble (G-INP) and received his PhD in Physics of materials at University Joseph Fourier, Grenoble France (1993) on crystallographic investigation of functional magnetic materials. He joined the CNRS in 1995 and became responsible for a neutron diffractometer at the Institut Laue Langevin. Professor of Physics since 2001 he is author of more than 400 scientific articles and specialist of structural and magnetic properties of oxides and intermetallic compounds for applications ranging from hard magnets to soft magnetic materials.

Viorel Pop received the B.Sc. degree in physics, M.Sc. Degree in condensed matter physics and Ph.D. degree in physics from the Babes-Bolyai University Cluj-Napoca, Romania, in 1981, 1982 and 1993, respectively. He was employed by Institute for Nuclear Power Reactors, Piteşti, Romania (1982–1983), Institute for Atomic Physics, IFTM, Bucharest (1983–1990) and now is professor at University Babes-Bolyai. He was invited professor or invited researcher at Joseph-Fourier University Grenoble, University of Augsburg, Nantes University, Chemnitz University of Technology, ENEA, Frascati (Rome) and CNRS Grenoble.Research field: magnetism and magnetic materials - synthesis, structural and magnetic properties of polycrystalline and nanocrystalline/nanocomposite materials. He published more than 150-refereed publications (more than 120 in ISI international journals), 2 books as author, 2 books as editor and he leaded more than 15 research projects. Hirsch index: 18 (ISI Web of Science) Researcher ID: http://www.researcherid.com/rid/C-4776-2011 ORCID: http://orcid.org/0000-0001-5125-4412

ORCID

R. Hirian http://orcid.org/0000-0002-4466-6838

Additional information

Funding

We acknowledge the financial support from the Romanian Ministry of Education and Research (Ministerul Educatiei si Cercetarii Stiintifice) [grant PN-II-RU-TE-2014-4-2360].