The compound Sr₃Ti₂O₇and its structure

Symmetry analysis for the Ruddlesden-Popper systems Ca3Mn2O7and CaHarris1 2011Phys. Rev. B

“…Applying a magnetic field H Z in the Zdirection (i.e., parallel to q 1 ) will cause the free energy of the variables 2 ≡ [P Y ,F Z ,G X (q 2 ),Q 2 (q 2 )] to be less than that of the variables 1 ≡ [P Z ,F Y ,G X (q 1 ),Q 2 (q 1 )] because of the magnetic field energy −H Z F Z . Similarly, applying an electric field in the Y direction will cause the free energy of the variables 2 to be less than that of the variables 1 . How large a magnetic or electric field is required to rotate the system from the left to the right panel of Fig.…”

“…As before, we introduce OP's Q 2 (q 1 ) and Q 2 (q 2 ) by considering the free energy for which the distortion from tetragonal is given by Q 2 (q 1 ) times the distortion for q 1 plus Q 2 (q 2 ) times the distortion for q 2 . As in Eq.…”

Simulation of STEM-HAADF Image Contrast of Ruddlesden–Popper Faulted LaNiO3 Thin Films

“…The earlier observations of RP faults were based on diffraction results 8,9 , but they have also been imaged more recently using advanced microscopy tools, especially by atomic resolution on scanning transmission electron microscope -high-angle annular dark-field imaging (STEM-HAADF) because of its chemical sensitivity at high and low spatial resolution through Z-contrast 10 . Lately, based on HAADF contrast and Electron Energy Loss Spectroscopy(EELS) measurements, some atomistic models have been proposed to describe the geometry and origin of the RP faults in different perovskite materials such as LaNiO 3 This type of defects critically affects the electronic properties of these compounds, as they can trigger secondary effects as cation diffusion through the defects path or even induce exciting new properties at the interfaces 19 .…”

Improvement of the Thermoelectric Properties of (Sr0.9La0.1)3Ti2O7 by Ag Addition

“…However, their thermoelectric performance is still low due to the fact that the κ value of SrTiO 3 bulk crystal (∼12 W/mK) [10] at room temperature is approximately one order of magnitude larger than that of Bi 2 Te 3 [8]. In order to efficiently reduce the κ value of SrTiO 3 , one way is its layered perovskite-type SrO(SrTiO 3 ) n or Sr n+1 Ti n O 3n+1 (n = integer) termed as Ruddlesden-Popper (RP) phase [11,12], which have a layered structure composed of alternate stacks of rock salt SrO layer and perovskite (SrTiO 3 ) n block layer along the c-axis. This layer structure can exhibit rather low κ values because phonon scattering occurs efficiently at the interface between SrO layer and (SrTiO 3 ) n block layer.…”