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Title: Substrate-dependent post-annealing effects on the strain state and electrical transport of epitaxial La{sub 5/8-y}Pr{sub y}Ca{sub 3/8}MnO{sub 3} films

Large scale electronic phase separation (EPS) between ferromagnetic metallic and charge-ordered insulating phases in La{sub 5/8-y}Pr{sub y}Ca{sub 3/8}MnO{sub 3} (y = 0.3) (LPCMO) is very sensitive to the structural changes. This work investigates the effects of post-annealing on the strain states and electrical transport properties of LPCMO films epitaxially grown on (001){sub pc} SrTiO{sub 3} (tensile strain), LaAlO{sub 3} (compressive strain) and NdGaO{sub 3} (near-zero strain) substrates. Before annealing, all the films are coherent-epitaxial and insulating through the measured temperature range. Obvious change of film lattice is observed during the post-annealing: the in-plane strain in LPCMO/LAO varies from −1.5% to −0.1% while that in LPCMO/STO changes from 1.6% to 1.3%, and the lattice of LPCMO/NGO keeps constant because of the good lattice-match between LPCMO and NGO. Consequently, the varied film strain leads to the emergence of metal-insulator transitions (MIT) and shift of the critical transition temperature in the electrical transport. These results demonstrate that lattice-mismatch combined with post-annealing is an effective approach to tune strain in epitaxial LPCMO films, and thus to control the EPS and MIT in the films.
Authors:
; ; ; ; ;  [1] ;  [2] ; ; ; ;  [1] ;  [3]
  1. National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)
  2. CAS Key Laboratory of Materials for Energy Conversion and Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026 (China)
  3. (China)
Publication Date:
OSTI Identifier:
22300096
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 6; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; CONTROL; CRYSTAL DEFECTS; EPITAXY; FILMS; LANTHANUM OXIDES; STRAINS; STRONTIUM TITANATES; SUBSTRATES; TEMPERATURE RANGE; TRANSITION TEMPERATURE