Interface Structures of La_0.67Sr_0.33MnO₃/SrTiO₃ Superlattices Studied by TEM and EELS

Abstract

The layered structures of La 0.67 Sr 0.33 MnO 3 /SrTiO 3 superlattices have been investigated by energy filtered transmission electron microscopy (EFTEM) and spatially resolved electron energy loss spectroscopy (EELS). A general picture of the elemental distribution of the chemically modulated layers was given by the EFTEM images. Chemical shift in both Ti-L 2,3 and Mn-L 2,3 edges, together with an appearance of distinctive shoulders in both Mn-L 3 and Mn-L 2 edges at the interfacial region were observed. These electronic structure changes suggest a stronger crystal field and/or a partial loss of oxygen at the interfaces, accounting for the observed oscillatory exchange coupling and enhanced magnetoresistance in such superlattices.

Threading dislocations in La 0.67 Sr 0.33 MnO 3 /SrTiO 3 superlattice

“…3a and b are taken from the LSMO layer and the lower ones are taken from the LSMO/STO interface. The similar trends of peak shifting are observed for both Mn-L 2,3 and Ti-L 2,3 edges when the electron probes move from the LSMO layer to the LSMO/STO interface: the energy positions of Mn-L 2,3 and Ti-L 2,3 edges shifted towards lower-energy losses (red-shifted), suggesting a local understoichiometry of oxygen around Mn and Ti at the interfacial region [11]. The large lattice mismatch and non-stoichiometry in the near-interface region all contribute to the formation of TDs.…”

“…In our previous studies, we have observed oscillatory exchange coupling and enhanced magnetoresistance in such superlattices [9, 10]. The study on the electronic structures evolution across the interface of the superlattice provides a plausible explanation for the observed physical properties, that is, a stronger crystal field and/or a partial loss of oxygen at the interfacial regions [11]. In this reported work, we looked at different aspect of the LSMO/STO superlattices, studied the defects nature and the evolution of defects across multiple interfaces, by analysing details of the cross‐sectional bright field TEM micrograph.…”

Exceptional electrochemical performance of porous TiO2–carbon nanofibers for lithium ion battery anodes

“…The non-splitting Ti-L 3 /L 2 edge suggests the octahedral coordination of titanium atoms with oxygen. [23][24][25] The O-K edge shows a single peak, conrming the unoccupied oxygen p state. 26 The Raman spectrum analyses also conrm the presence of anatase TiO 2 and some graphitic carbon in the obtained materials (Fig.…”

Electric Field Modulation on Special Interfacial Magnetic States in Tetragonal La2/3Sr1/3MnO3/BiFeO3 Heterostructures

“…Hence, we focus on the tetragonal BFO and apply it to the multifunctional devices. Spintronic devices are studied intensively in various fields, such as the organometallic spin filter, − molecular spin-valve devices, and oxide spintronics. ,− Half-metallic materials are crucial to the spintronic devices, owing to the 100% spin polarization. , LSMO with a high ferromagnetic Curie temperature of 370 K is a prototypical ferromagnetic half-metallic material, which shows a magnetoelectric effect via accompanying with various ferroelectric materials, like BaTiO 3 , Pb­(Zr 0.52 Ti 0.48 )­O 3 , and rhombohedral BFO. ,− …”