Epitaxy Induced Highly Ordered Sm2Co17-SmCo5Nanoscale Thin-Film Magnets

Shalini Sharma, Alexander Zintler, Damian Günzing, Johanna Lill, Debora Motta Meira, Robert Eilhardt, Harish Kumar Singh, Ruiwen Xie, Georgia Gkouzia, Márton Major, Iliya Radulov, Philipp Komissinskiy, Hongbin Zhang, Konstantin Skokov, Heiko Wende, Yukiko K. Takahashi, Katharina Ollefs, Leopoldo Molina-Luna, Lambert Alff

Research output: Contribution to journalArticlepeer-review

Abstract

Utilizing the molecular beam epitaxy technique, a nanoscale thin-film magnet of c-axis-oriented Sm2Co17 and SmCo5 phases is stabilized. While typically in the prototype Sm(Co, Fe, Cu, Zr)7.5-8 pinning-type magnets, an ordered nanocomposite is formed by complex thermal treatments, here, a one-step approach to induce controlled phase separation in a binary Sm-Co system is shown. A detailed analysis of the extended X-ray absorption fine structure confirmed the coexistence of Sm2Co17 and SmCo5 phases with 65% Sm2Co17 and 35% SmCo5. The SmCo5 phase is stabilized directly on an Al2O3 substrate up to a thickness of 4 nm followed by a matrix of Sm2Co17 intermixed with SmCo5. This structural transition takes place through coherent atomic layers, as revealed by scanning transmission electron microscopy. Highly crystalline growth of well-aligned Sm2Co17 and SmCo5 phases with coherent interfaces result in strong exchange interaction, leading to enhanced magnetization and magnetic coupling. The arrangement of Sm2Co17 and SmCo5 phases at the nanoscale is reflected in the observed magnetocrystalline anisotropy and coercivity. As next-generation permanent magnets require designing of materials at an atomic level, this work enhances our understanding of self-assembling and functioning of nanophased magnets and contributes to establishing new concepts to engineer the microstructure for beyond state-of-the-art magnets.

Original languageEnglish
Pages (from-to)32415-32423
Number of pages9
JournalACS Applied Materials and Interfaces
Volume13
Issue number27
DOIs
Publication statusPublished - 2021 Jul 14
Externally publishedYes

Keywords

  • coherent interfaces
  • MBE
  • microstructure designing
  • nanophased magnets
  • ordered nanocomposites
  • SmCo
  • SmCo

ASJC Scopus subject areas

  • Materials Science(all)

Fingerprint

Dive into the research topics of 'Epitaxy Induced Highly Ordered Sm<sub>2</sub>Co<sub>17</sub>-SmCo<sub>5</sub>Nanoscale Thin-Film Magnets'. Together they form a unique fingerprint.

Cite this