Observation of Superconductivity above 200 K in Pressure-Stabilized Cubic (Y,Ce)H₁₀

Clathrate hydrides have attracted considerable attention for their high-temperature superconductivity under high pressure, motivating the enhancement of their superconducting temperature (T_c) through metal doping as a compelling pursuit. Here, we introduce relatively lighter Y into the Ce-H system to tailor its superconductivity, yielding a substituted face-centered cubic (Y,Ce)H₁₀ phase that incorporates a crucial YH₁₀ structural motif unattainable in the binary Y-H system. Remarkably, the resulting (Y,Ce)H₁₀ exhibits superconductivity with a maximum T_c of 206 K, an ∼80% enhancement relative to CeH₁₀, placing it among the very few hydride superconductors that surpass the 200 K regime. Our results demonstrate that the metal element exerts a crucial influence on the superconductivity of clathrate hydrides, with the presence of YH₁₀ units clearly enhancing superconductivity and underscoring elemental substitution as a feasible strategy to further promote superconductivity.