Beyond a phenomenological description of magnetostriction

A. H. Reid; X. Shen; P. Maldonado; T. Chase; E. Jal; P. Granitzka; K. Carva; R. K. Li; J. Li; L. Wu; T. Vecchione; T. Liu; Z. Chen; D. J. Higley; N. Hartmann; R. Coffee; J. Wu; G. L. Dakowski; W. Schlotter; H. Ohldag; Y. K. Takahashi; V. Mehta; O. Hellwig; A. Fry; Y. Zhu; J. Cao; E. E. Fullerton; J. Stöhr; P. M. Oppeneer; X. J. Wang; H. A. Dürr

arXiv · 1602.04519

Beyond a phenomenological description of magnetostriction

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Abstract

We use ultrafast x-ray and electron diffraction to disentangle spin-lattice coupling of granular FePt in the time domain. The reduced dimensionality of single-crystalline FePt nanoparticles leads to strong coupling of magnetic order and a highly anisotropic three-dimensional lattice motion characterized by a- and b-axis expansion and c-axis contraction. The resulting increase of the FePt lattice tetragonality, the key quantity determining the energy barrier between opposite FePt magnetization orientations, persists for tens of picoseconds. These results suggest a novel approach to laser-assisted magnetic switching in future data storage applications.

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A. H. Reid, X. Shen, P. Maldonado, T. Chase, E. Jal, P. Granitzka, K. Carva, R. K. Li, J. Li, L. Wu, T. Vecchione, T. Liu, Z. Chen, D. J. Higley, N. Hartmann, R. Coffee, J. Wu, G. L. Dakowski, W. Schlotter, H. Ohldag, Y. K. Takahashi, V. Mehta, O. Hellwig, A. Fry, Y. Zhu, J. Cao, E. E. Fullerton, J. Stöhr, P. M. Oppeneer, X. J. Wang, H. A. Dürr. 2016-02-14. Beyond a phenomenological description of magnetostriction. https://arxiv.org/abs/1602.04519

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