Mössbauer-effect and microwave absorption experimental evidence unambiguously demonstrates the presence of slow, ~450 MHz, tunneling of magnetic europium between four equivalent sites in Eu8Ga16Ge30, a stoichiometric clathrate. Remarkably, six of the eight europium atoms, or 11% of the constituents in this solid, tunnel between these four sites separated by 0.55 Å. The off centering of the atoms or ions in crystalline clathrates appears to be a promising route for producing Rabi oscillators in solid-state materials.
V. Keppens and P. Bonville and G. S. Nolas and F. Grandjean and G. J. Long and H. M. Christen and B. C. Chakoumakos and B. C. Sales and D. Mandrus and R. P. Hermann, "Direct Experimental Evidence for the Atomic Tunneling of Europium in Crystalline Eu₈Ga₁₆Ge₃₀," Physical Review Letters, American Physical Society (APS), Jan 2006.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevLett.97.017401
National Science Foundation (U.S.)
United States. Department of Energy
Keywords and Phrases
Eu8Ga16Ge30; Mössbauer-Effect; Microwave Absorption; Stoichiometric Clathrate
Article - Journal
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