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Register a new userMagnetoelastic standing waves induced in UO$_{2}$ by microsecond magnetic field pulses
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Added by
Rico Sch\\\"onemann
Publication date
2021
fields
Physics
and research's language is
English
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Magnetoelastic measurements in the piezomagnetic antiferromagnet UO$_{2}$ were performed via the fiber Bragg grating method in magnetic fields up to $150,mathrm{T}$ generated by a single-turn coil setup. We show that in short timescales, order of a few micro seconds, pulsed-magnetic fields excite mechanical resonances at temperatures ranging from $10,mathrm{K}$ to $300,mathrm{K}$, in the paramagnetic as well as within the robust antiferromagnetic state of the material. These resonances, which are barely attenuated within the 100 ms observations, are attributed to the strong magnetoelastic coupling in UO$_{2}$ combined with the high crystallographic quality of the single crystal samples. They compare well with mechanical resonances obtained by a resonant ultrasound technique and superimpose on the known non-monotonic magnetostriction background. A clear phase-shift of $pi$ in the lattice oscillations is, unexpectedly, observed in the antiferromagnetic state when the magnetic field overcomes the piezomagnetic switch-field $H_c simeq -18,mathrm{T}$. We further present simulations and a theoretical argument to explain the observed phenomena.
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