Experiments conducted on the EKAP facility at the Russian Federal Nuclear Center–VNIITF concerning the stabilization of Rayleigh–Taylor instability-induced mixing in miscible liquids by the formation of a molecular diffusion (or transitional) layer between the liquids initially were described. The experiments had an Atwood number of 1/3. The acceleration was 3500 times that of Earth's gravity, and several values of diffusion layer thickness were considered. The experiments showed that the growth of the turbulent mixing zone could be delayed by adjusting the amplitude of the initial perturbations and the characteristic thickness of the diffusion layer. This has been observed in experiments conducted with water and mercury. The mixing layer evolution was imaged using X-ray radiography.