Intrinsic Magnetic Properties of a Highly Anisotropic Rare‐Earth‐Free Fe2P‐Based Magnet

• Published in: Advanced functional materials Vol. 32; no. 4
• Main Authors: He, Yangkun, Adler, Peter, Schneider, Sebastian, Soldatov, Ivan, Mu, Qingge, Borrmann, Horst, Schnelle, Walter, Schaefer, Rudolf, Rellinghaus, Bernd, Fecher, Gerhard H., Felser, Claudia
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2022
• Subjects: Anisotropy; Corrosion resistance; Curie temperature; Earth; Fe 2P; High temperature; Interlayers; Magnetic properties; Magnetic saturation; Magnetism; magnetocrystalline anisotropy; Materials science; Permanent magnets; Phase stability; Room temperature; Single crystals
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202107513

Permanent magnets are applied in many large‐scale and emerging applications and are crucial components in numerous established and newly evolving technologies. Rare‐earth magnets exhibit excellent hard magnetic properties; however, their applications are limited by the price and supply risk of the strategic rare‐earth elements. Therefore, there is an increasing demand for inexpensive magnets without strategic elements. Here, the authors report the intrinsic highly‐anisotropic magnetic properties of Co and Si co‐doped single crystals (Fe1−yCoy)2P1−xSix (y ≈ 0.09). Co increases Curie temperature TC; Si doping decreases magnetocrystalline anisotropy K1 and also increases TC significantly because of the enhanced interlayer interaction. The maximum room temperature magnetocrystalline anisotropy K1 = 1.09 MJ m−3 is achieved for x = 0.22, with saturation magnetization µ0Ms = 0.96 T and TC = 506 K. The theoretical maximum energy product is one of the largest for any magnet without a rare earth or Pt. Besides its promising intrinsic magnetic properties and absence of any strategic elements, other advantages are phase stability at high temperatures and excellent corrosion resistance, which make this material most promising for permanent magnetic development that will have a positive influence in industry and daily life. The authors report the intrinsic highly‐anisotropic magnetic properties of Co and Si co‐doped single crystals (Fe1−yCoy)2P1−xSix. A maximum room temperature magnetocrystalline anisotropy of 1.09 MJ m–3 is achieved, with a saturation magnetization of 0.96 T and a Curie temperature of 506 K, making this material promising for permanent magnets.