Superconducting radio-frequency acceleration involves creating strong electromagnetic fields inside a cryogenically cooled superconducting vessel that can be used to accelerate charged particles. The superconducting state is limited by the ability of the material to repel magnetic flux penetration from the strong surface fields. New materials or new material treatments are being developed to allow higher fields and more efficient acceleration before flux penetrates the material. Recent experiments at the TRIUMF muSR facility have shown that coating niobium with a high Tc material (like Nb3Sn or MgB2) of variable coating thickness can increase the field of first flux penetration by 40% with respect to a non-coated sample. The measurements suggest a path forward to increase the performance of niobium SRF resonators through modification to the surface.