Superior Superconducting Properties Realized in Quaternary La-Y-Ce Hydrides at Moderate Pressures.

The recent revolution in the superconductivity field stems from hydride superconductors. Multicomponent hydrides provide a crucial platform for tracking high-temperature superconductors. Besides high superconducting transition temperature (T-c), achieving both giant upper critical magnetic field [mu H-0(c2)(0)] and high critical current density [J(c)(0)] is also key to the latent potential of the application for hydride superconductors. In this work, we have successfully synthesized quaternary La-Y-Ce hydrides with excellent properties under moderate pressure by using the concept of "entropy engineering." The obtained temperature dependence of the resistance provides evidence for the superconductivity of Fm3m-(La,Y,Ce)H-10, with the maximum T-c similar to 190 K (at 112 GPa). Notably, Fm3m-(La,Y,Ce)H-10 boasts exceptional properties: mu H-0(c2)(0) reaching 292 T and J(c)(0) surpassing 4.61 x 10(7) A/cm(2). Compared with the binary LaH10/YH10, we find that the Fm3m structure in (La,Y,Ce)H-10 can be stable at relatively low pressures (112 GPa). These results indicate that multicomponent hydrides can significantly enhance the superconducting properties and regulate stabilizing pressure through the application of "entropy engineering." This work stimulates the experimental exploration of multihydride superconductors and also provides a reference for the search of room-temperature superconductors in more diversified hydride materials in the future.