Latent instabilities in metallic LaNiO3 films by strain control of Fermi-surface topology

Abstract

Strain control is one of the most promising avenues to search for new emergent phenomena in transition-metal-oxide films. Here, we investigate the strain-induced changes of electronic structures in strongly correlated LaNiO3 (LNO) films, using angle-resolved photoemission spectroscopy and the dynamical mean-field theory. The strongly renormalized eg-orbital bands are systematically rearranged by misfit strain to change its fermiology. As tensile strain increases, the hole pocket centered at the A point elongates along the kz-axis and seems to become open, thus changing Fermi-surface (FS) topology from three- to quasi-two-dimensional. Concomitantly, the FS shape becomes flattened to enhance FS nesting. A FS superstructure with Q1 = (1/2,1/2,1/2) appears in all LNO films, while a tensile-strained LNO film has an additional Q2 = (1/4,1/4,1/4) modulation, indicating that some instabilities are present in metallic LNO films. Charge disproportionation and spin-density-wave fluctuations observed in other nickelates might be their most probable origins.

Electronic structure of buried LaNiO3 layers in (111)-oriented LaNiO3/LaMnO3 superlattices probed by soft x-ray ARPES

“…However, the small electron escape depth in VUV-ARPES experiments has limited most studies to the top layer of oxide thin films. 2,[9][10][11] Most members of the nickel based perovskite oxides RNiO 3 (R is a trivalent rare earth element) exhibit a metal-to-insulator transition as a function of temperature. [12][13][14][15] In addition, a transition from a paramagnetic to an antiferromagnetic ground state is observed in these compounds.…”

Multiple strain-induced phase transitions inLaNiO3thin films

“…These strain-induced structural transformations are central to understand some dramatic changes of physical properties such as metal-insulator transitions observed on LNO thin films and LNO multilayers [3][4][5][6][7][8][9], or to rationalize reported spectroscopic results. For instance, Chakhalian et al [10], Freeland et al [11], and Tung et al [12] reported x-ray absorption results at Ni edges of LNO films grown on LaAlO 3 (LAO) and SrTiO 3 (STO) substrates, which impose compressive and tensile stresses, respectively, supported by first-principles density functional theory (DFT) calculations.…”

“…The interest is mainly motivated by a strong similarity of low-spin Ni 3+ ions, having an electronic configuration 3d 7 : t 2g 6 e g 1 , to Cu 2+ ions in the high-temperature superconducting cuprates (HTSCs, with 3d 9 : t 2g 6 e g 3 ). In the HTSC materials, due to their layered structure, the z 2 orbitals are pushed down in energy and are fully occupied, whereas conductivity is confined to the partially occupied x 2 -y 2 orbitals.…”

Quantifying electronic correlation strength in a complex oxide: A combined DMFT and ARPES study ofLaNiO3

“…LaNiO 3 has already been characterized experimentally via ARPES [14][15][16], optical conductivity [17][18][19], and thermodynamic measurements [20][21][22], as well as theoretically with DFT [23][24][25], DFT + DMFT [6,8,[26][27][28][29], and model system [30][31][32] calculations, and a variety of measurements of m /m have previously appeared (to be discussed more later). ARPES offers a particularly direct measure of a material's mass enhancement via momentum-resolved access to the electronic Green's function, which is the fundamental quantity that characterizes electron propagation in a material:…”

“…The MIT temperature is related to the amplitude of the NiO 6 octahedral rotations, which in bulk materials is controlled by the size of the R cation. In addition, studies of ultrathin films of LaNiO 3 grown epitaxially on different substrates [10][11][12][13][14][15] show that both the critical film thickness for an MIT and the coefficient of the T 2 term in the resistivity depend on the value of the epitaxially induced strain. We thus expect that in LaNiO 3 the correlation strength is determined by a subtle interplay between a basic interaction parameter and the precise crystal structure.…”