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Updated: Jan 13, 2026

Fabrication and Optimization of Type II Silicon Clathrate Films
Published on: October 14, 2025
Dumbbells of five-connected silicon atoms and superconductivity in the binary silicides MSi3 (M = Ca, Y, Lu)
Ulrich Schwarz1, Aron Wosylus, Helge Rosner
1Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany. schwarz@cpfs.mpg.de
Abstract:
The new metastable binary silicides MSi(3) (M = Ca, Y, Lu) have been synthesized by high-pressure, high-temperature reactions at pressures between 12(2) and 15(2) GPa and temperatures from 900(100) to 1400(150) K. The atomic patterns comprise intricate silicon layers of condensed molecule-like Si(2) dimers. The alkaline-earth element adopts the oxidation state +2, while the rare-earth and transition metals realize +3. All of the compounds exhibit BCS-type superconductivity with weak electron-phonon coupling below critical temperatures of up to 7 K.
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