This thesis explores an amazing family of oxide compounds - the nickelates - known for their metal-to-insulator transition and, in the case of LaNiO3, to be a possible building block for designing a synthetic high Tc superconductor. Competition between various fascinating phases makes these materials very sensitive to external parameters and it is thus possible to dramatically tune their properties. This work on ultrathin LaNiO3 and the solid solution Nd1-xLaxNiO3 has important implications for the search for superconductivity in this class of materials.