Growth of Ruddlesden–Popper phase La4Ni3O10 thin film on LaAlO3 substrate via pulsed laser deposition method

Pulsed laser deposition (PLD) is a promising technique for thin-film growth from the perspectives of both practical applications and the development of fundamental materials science. Recently, La3Ni2O7 thin films, belonging to the layered Ruddlesden–Popper (RP) nickelates Lan+1NinO3n+1, grown on substrates inducing compressive strain due to lattice mismatch, have attracted considerable attention as a new class of high transition-temperature superconductors at ambient pressure. Although the emergence of superconductivity in the related RP-type nickelate La4Ni3O10 thin film is anticipated, the growth of an oriented thin film along the c-axis with compressive strain has not been reported using the PLD process. In this study, we investigate the thin-film growth of La4Ni3O10 using the PLD technique on a LaAlO3 substrate that imposes a compressive strain. X-ray diffraction analysis and transmission electron microscopy reveal that well-oriented La4Ni3O10 phases can be grown on the LaAlO3 substrate. Although superconductivity is absent in the grown film, the phase formation of La4Ni3O10 on the LaAlO3 substrate via the PLD process is the first step for the realization of ambient-pressure superconductivity in this system.