Structural and magnetic properties of high anisotropy HfCo$_{7-x}$Fe$_{x}$ alloys

ORAL

Abstract

An increasing demand of rare-earth elements in recent years intensifies the search for rare-earth free permanent magnetic materials with magnetocrystalline anisotropy $K_{1}$ = 1 MJ/m$^{3}$. The present study reports melt-spun HfCo$_{7}$ alloys with a high $K_{1}$ of 1.3 MJ/m$^{3}$ along with an appreciable saturation-magnetic polarization ($J_{s})$ of 8.9 kG. A substitution of Fe for Co in HfCo$_{7-x}$Fe$_{x}$ further improves $K_{1}$ and $J_{s}$ to 1.5 MJ/m$^{3}$ and 10.4 kG, respectively. XRD studies of HfCo$_{7}$ are in agreement with an orthorhombic structure and also reveal a lattice expansion on substituting Fe for Co. These results show that HfCo$_{7-x}$Fe$_{x}$ can be a promising candidate for permanent-magnet and other significant applications. In brief, the structural and magnetic properties of HfCo$_{7-x}$Fe$_{x}$ alloys (0 $\le $ x $\le $ 1) investigated using XRD, EDX, TEM, and SQUID magnetometer will be presented.

*This work is supported by DOE (D.J.S.), ARPA-E (B.B., J.E.S.), BREM (B.D., R.S.), and NCMN (S.R.V.)

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Authors

  • Balamurugan Balasubramanian

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.

  • Bhaskar Das

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.

  • Ralph Skomski

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.

  • Shah Valloppilly

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.

  • Jeffrey Shield

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.

  • David Sellmyer

    • University of Nebraska-Lincoln
    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588.