Pressure Temperature evolution of the Charge density wave and structural transition of the superconducting trilayer Nickelate La4Ni3O10

La4Ni3O10 develops below 140K an incommensurate Charge and itinerant Spin density wave with qc=0.24b* which is believed to be associated to the Nickel atoms. Under pressure, a superconducting pocket appears above Pc=15GPa with a maximum of critical temperature up to 30K. A possible structural change due to a tilt of the octahedra of NiO6 is concomitant at this same pressure Pc. This proposal aims to determine the CDW and structural phase diagram of this trilayer nickelate, in particular at low temperature by a careful analysis the evolution of the intensity and the q vector of the CDW under pressure on single crystal of La4Ni3O10. These information are very important to understand the role of the density wave on one hand and the tilt of the NiO6 octahedra on an other hand, on the emergence of the superconductivity in the nickelates