Campus Units

Physics and Astronomy, Chemistry, Materials Science and Engineering, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-24-2014

Journal or Book Title

Nature Communications

Volume

5

First Page

3333

DOI

10.1038/ncomms4333

Abstract

Large magnetic anisotropy and coercivity are key properties of functional magnetic materials and are generally associated with rare earth elements. Here we show an extreme, uniaxial magnetic anisotropy and the emergence of magnetic hysteresis in Li2(Li1−xFex)N. An extrapolated, magnetic anisotropy field of 220 T and a coercivity field of over 11 T at 2 K outperform all known hard ferromagnets and single-molecular magnets. Steps in the hysteresis loops and relaxation phenomena in striking similarity to single-molecular magnets are particularly pronounced for x≪1 and indicate the presence of nanoscale magnetic centres. Quantum tunnelling, in the form of temperature-independent relaxation and coercivity, deviation from Arrhenius behaviour and blocking of the relaxation, dominates the magnetic properties up to 10 K. The simple crystal structure, the availability of large single crystals and the ability to vary the Fe concentration make Li2(Li1−xFex)N an ideal model system to study macroscopic quantum effects at elevated temperatures and also a basis for novel functional magnetic materials.

Comments

This is a manuscript of an article published as Jesche, Anton, R. W. McCallum, S. Thimmaiah, J. L. Jacobs, V. Taufour, A. Kreyssig, R. S. Houk, S. L. Bud’Ko, and P. C. Canfield. "Giant magnetic anisotropy and tunnelling of the magnetization in Li 2 (Li 1− x Fe x) N." Nature Communications 5 (2014): 3333. DOI: 10.1038/ncomms4333. Posted with permission.

Copyright Owner

Macmillan Publishers Limited

Language

en

File Format

application/pdf

Published Version

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