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S. Paschen, C. Gspan, W. Grogger, M. Dienstleder, St. Laumann, P. Pongratz, H. Sassik, J. Wernisch, A. Prokofiev:
"Investigation of Yb substitution in the clathrate phase Eu₈Ga₁₆Ge₃₀";
Journal of Crystal Growth, 310 (2008), 1853 - 1858.

Attempts to introduce rare earth elements other than Eu as guest atoms into intermetallic clathrates have remained elusive to date. Besides fundamental interest, their motivation is to create "strongly correlated" clathrates with correlation-enhanced "giant" thermopower values in addition to the much discussed low thermal conductivities, and thus with enhanced thermoelectric figures-of-merit. In Eu clathrates no sizeable hybridization of the 4f electrons with the conduction electrons is observed. Here we present our attempts to incorporate Yb in Eu₈Ga₁₆Ge₃₀. Yb leads to strong correlation effects in many intermetallic compounds. Along with the standard melting and annealing procedure an alternative route, namely quick quenching of the melt by melt spinning, was tested. Samples obtained in both ways were investigated by XRD, SEM/EDX, and TEM/EDX techniques. No sizable substitution of Eu by Yb in the clathrate phase was found.

Clathrate; Eu₈Ga₁₆Ge₃₀; Yb; Melt spinning

http://dx.doi.org/10.1016/j.jcrysgro.2007.11.126

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