DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: X-ray nanodiffraction studies of ionically controlled nanoscale phase separation in cobaltites

Journal Article · · Physical Review Materials
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [3];  [4];  [5];  [6];  [7];  [1];  [1]
  1. Univ. of California Davis, Davis, CA (United States). Dept. of Materials Science and Engineering
  2. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
  3. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). NIST Center for Neutron Research
  4. Univ. of California Davis, Davis, CA (United States). Dept. of Physics
  5. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials
  6. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Proton Source
  7. Univ. of California Davis, Davis, CA (United States). Dept. of Physics; Georgetown Univ., Washington, D.C. (United States). Dept. of Physics

Complex oxide heterostructures provide access to emergent functional and structural phases that are not present in the bulk constituent materials. In this Rapid Communication, we focus on $$La_{0.67}Sr_{0.33}CoO_3$$ (LSCO)/Gd heterostructures due to the high oxygen ion conductivity, as well as the coupled magnetic and electronic properties of LSCO, which are strongly dependent on the oxygen stoichiometry. This combination of properties enables the ionic control of the functional properties of LSCO thin films through the presence of oxygen getter layers such as Gd.We utilize x-ray nanodiffraction to directly image the nanoscale morphology of LSCO thin films as they are progressively transformed from the equilibrium perovskite phase to the metastable brownmillerite (BM) phase with increasing Gd thickness. Our studies show the coexistence of perovskite and BM phases with a critical oxygen vacancy concentration threshold which leads to the formation of extended BM filaments. In addition to lateral phase separation, we observed phase separation within the film thickness possibly due to pinning of the perovskite and BM phases by the substrate/LSCO and LSCO/Gd interface, respectively. Our studies provide a nanoscale survey of the phase separation in the cobaltites and shed light on the formation of the metastable BM phase.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); University of California–Davis, Davis, CA (United States); National Science Foundation (NSF)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1562285
Alternate ID(s):
OSTI ID: 1547991; OSTI ID: 1573808; OSTI ID: 1581604
Journal Information:
Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 8 Vol. 3; ISSN PRMHAR; ISSN 2475-9953
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (40)

Electron-Beam-Induced Perovskite-Brownmillerite-Perovskite Structural Phase Transitions in Epitaxial La 2/3 Sr 1/3 MnO 3 Films journal February 2014
Influence of TEM specimen preparation on chemical composition of Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals journal July 2014
Comparison of topotactic fluorination methods for complex oxide films journal June 2015
Efficient modeling of Bragg coherent x-ray nanobeam diffraction journal January 2015
Probing oxygen vacancy concentration and homogeneity in solid-oxide fuel-cell cathode materials on the subunit-cell level journal August 2012
Comparison of TEM specimen preparation of perovskite thin films by tripod polishing and conventional ion milling journal September 2008
In situ examination of oxygen non-stoichiometry in La 0.80 Sr 0.20 CoO 3−δ thin films at intermediate and low temperatures by x-ray diffraction journal April 2014
Nanoscale Hard X-Ray Microscopy Methods for Materials Studies journal July 2013
Glassy ferromagnetism and magnetic phase separation in La 1 − x Sr x CoO 3 journal May 2003
Strain-Induced Spin States in Atomically Ordered Cobaltites journal January 2012
Voltage-Controlled Topotactic Phase Transition in Thin-Film SrCoO x Monitored by In Situ X-ray Diffraction journal January 2016
Ion-gel-gating-induced oxygen vacancy formation in epitaxial L a 0.5 S r 0.5 Co O 3 − δ films from in operando x-ray and neutron scattering journal December 2017
Scavenging of oxygen from SrTiO 3 during oxide thin film deposition and the formation of interfacial 2DEGs journal March 2017
Magnetic and electronic properties in hole-doped manganese oxides with layered structures: La 1 − x Sr 1 + x MnO 4 journal February 1995
Systematic study of insulator-metal transitions in perovskites RNiO3 (R=Pr,Nd,Sm,Eu) due to closing of charge-transfer gap journal April 1992
Direct imaging of structural changes induced by ionic liquid gating leading to engineered three-dimensional meso-structures journal August 2018
Ionic tuning of cobaltites at the nanoscale journal October 2018
Tuning the magnetic properties of La Co O 3 thin films by epitaxial strain journal January 2008
Electric-field control of tri-state phase transformation with a selective dual-ion switch journal May 2017
Structural details and magnetic order of La 1 − x Sr x CoO 3 ( x <~ 0 . 3 ) journal January 1999
Oxygen stoichiometry, ferromagnetism, and transport properties of La 2 − x NiMnO 6 + δ journal August 2003
Memristive switching mechanism for metal/oxide/metal nanodevices journal June 2008
Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge journal August 2013
Controllable positive exchange bias via redox-driven oxygen migration journal March 2016
A hard X-ray nanoprobe beamline for nanoscale microscopy journal September 2012
Octahedral cation site disorder effects on magnetization in double-perovskite Sr2FeMoO6: Monte Carlo simulation study journal July 1999
Topotactic Phase Transformation of the Brownmillerite SrCoO 2.5 to the Perovskite SrCoO 3- δ journal July 2013
Effect of oxygen vacancies in the SrTiO 3 substrate on the electrical properties of the LaAlO 3 ∕ SrTiO 3 interface journal March 2007
Evidence for oxygen vacancy manipulation in La 1/3 Sr 2/3 FeO 3−𝜹 thin films via voltage controlled solid-state ionic gating journal April 2017
Perpendicular magnetic anisotropy via strain-engineered oxygen vacancy ordering in epitaxial L a 1 − x S r x Co O 3 − δ journal November 2018
Relationship between cation substitution and stability of perovskite structure in SrCoO3–δ-based mixed conductors journal January 2007
Coherent Bragg nanodiffraction at the hard X-ray Nanoprobe beamline
  • Hruszkewycz, S. O.; Holt, M. V.; Maser, J.
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 372, Issue 2010 https://doi.org/10.1098/rsta.2013.0118
journal March 2014
Fluorination of Epitaxial Oxides: Synthesis of Perovskite Oxyfluoride Thin Films journal January 2014
Lattice mismatch accommodation via oxygen vacancy ordering in epitaxial La 0.5 Sr 0.5 CoO 3-δ thin films journal July 2013
The role of B‐site cation disorder in diffuse phase transition behavior of perovskite ferroelectrics journal August 1980
Synthesis and Structural Characterization of La 1− x A x MnO 2.5 (A = Ba, Sr, Ca) Phases: Mapping the Variants of the Brownmillerite Structure journal November 2009
Reversible control of magnetism in La 0.67 Sr 0.33 MnO 3 through chemically-induced oxygen migration journal February 2016
The synthesis and complex anion-vacancy ordered structure of La0.33Sr0.67MnO2.42 journal July 2011
Coercivity enhancement driven by interfacial magnetic phase separation in SrTiO 3 (001)/Nd 0 . 5 Sr 0 . 5 CoO 3 journal July 2011
Epitaxial Oxygen Getter for a Brownmillerite Phase Transformation in Manganite Films journal January 2011