%X We report high-resolution measurements of the in-plane thermal expansion anisotropy in the vicinity of the electronic nematic phase in Sr3Ru2O7 down to very low temperatures and in varying magnetic field orientation. For fields applied along the c-direction, a clear second-order phase transition is found at the nematic phase, with critical behavior compatible with the two-dimensional Ising universality class (although this is not fully conclusive). Measurements in a slightly tilted magnetic field reveal a broken fourfold in-plane rotational symmetry, not only within the nematic phase, but extending towards slightly larger fields. We also analyze the universal scaling behavior expected for a metamagnetic quantum critical point, which is realized outside the nematic region. The contours of the magnetostriction suggest a relation between quantum criticality and the nematic phase. %I WILEY-V C H VERLAG GMBH %L discovery10134050 %P 450-456 %T Electronic nematicity and its relation to quantum criticality in Sr3Ru2O7 studied by thermal expansion %O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. %D 2013 %N 3 %V 250 %J Physica Status Solidi B - Basic Solid State Physics %A C Stingl %A RS Perry %A Y Maeno %A P Gegenwart