Included here are figures and other relevant data from the paper "Targeted Chemical Pressure Yields Tunable Millimeter-Wave 5G Dielectric with Unparalleled Performance" published online in Nature Materials on 23 December 2019 (https://doi.org/10.1038/s41563-019-0564-4). Abstract: Epitaxial strain can unlock enhanced properties in oxide materials but restricts substrate choice and maximum film thickness, above which lattice relaxation and property degradation occur. Here we employ a chemical alternative to epitaxial strain by providing targeted chemical pressure, distinct from random doping, to induce a ferroelectric instability with the strategic introduction of barium into today's best millimeter-wave tunable dielectric, the epitaxially strained 50 nm thick n = 6 (SrTiO3)nSrO Ruddlesden-Popper grown on (110) DyScO3. The defect mitigating nature of (SrTiO3)nSrO results in unprecedented low loss at frequencies up to 125 GHz. No barium-containing Ruddlesden-Popper titanates are known, but this atomically-engineered superlattice material, (SrTiO3)n?m(BaTiO3)mSrO, enables low-loss, tunable dielectric properties to be achieved with lower epitaxial strain and a 200 % improvement in the figure of merit at commercially-relevant millimeter-wave frequencies. As tunable dielectrics are key constituents for emerging millimeter-wave high-frequency devices in telecommunications our findings could lead to higher performance adaptive and reconfigurable electronics at these frequencies.