PMID- 25263577
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20150521
LR  - 20141216
IS  - 1435-8115 (Electronic)
IS  - 1431-9276 (Linking)
VI  - 20
IP  - 6
DP  - 2014 Dec
TI  - Atomic scale studies of La/Sr ordering in colossal magnetoresistant 
      La(2-2x)Sr(1+2x)Mn2O7 single crystals.
PG  - 1791-7
LID - 10.1017/S1431927614013075 [doi]
AB  - To date, it is unclear whether chemical order (or disorder) is in any way 
      connected to double exchange, electronic phase separation, or charge ordering 
      (CO) in manganites. In this work, we carry out an atomic resolution study of the 
      colossal magnetoresistant manganite La(2-2x)Sr(1+2x)Mn2O7 (LSMO). We combine 
      aberration-corrected electron microscopy and spectroscopy with spectroscopic 
      image simulations, to analyze cation ordering at the atomic scale in real space 
      in a number of LSMO single crystals. We compare three different compositions 
      within the phase diagram: a ferromagnetic metallic material (x=0.36), an 
      insulating, antiferromagnetic charge ordered (AF-CO) compound (x=0.5), which also 
      exhibits orbital ordering, and an additional AF sample (x=0.56). Detailed image 
      simulations are essential to accurately quantify the degree of chemical ordering 
      of these samples. We find a significant degree of long-range chemical ordering in 
      all cases, which increases in the AF-CO range. However, the degree of ordering is 
      never complete nor can it explain the strongly correlated underlying ordering 
      phenomena. Our results show that chemical ordering over distinct crystallographic 
      sites is not needed for electronic ordering phenomena to appear in manganites, 
      and cannot by itself explain the complex electronic behavior of LSMO.
FAU - Roldan, Manuel A
AU  - Roldan MA
AD  - 1Dpto. Fisica Aplicada III,Universidad Complutense de Madrid,28040 Madrid,Spain.
FAU - Oxley, Mark P
AU  - Oxley MP
AD  - 3Department of Physics and Astronomy,Vanderbilt University,Nashville,TN 
      37212,USA.
FAU - Li, Qing'an
AU  - Li Q
AD  - 4Argonne National Laboratory,Materials Science Division,Argonne,IL 60439,USA.
FAU - Zheng, Hong
AU  - Zheng H
AD  - 4Argonne National Laboratory,Materials Science Division,Argonne,IL 60439,USA.
FAU - Gray, K E
AU  - Gray KE
AD  - 4Argonne National Laboratory,Materials Science Division,Argonne,IL 60439,USA.
FAU - Mitchell, J F
AU  - Mitchell JF
AD  - 4Argonne National Laboratory,Materials Science Division,Argonne,IL 60439,USA.
FAU - Pennycook, Stephen J
AU  - Pennycook SJ
AD  - 5Department of Materials Science and Engineering,The University of 
      Tennessee,Knoxville,TN 37996,USA.
FAU - Varela, Maria
AU  - Varela M
AD  - 2Oak Ridge National Laboratory,Materials Science and Technology Division,Oak 
      Ridge,TN 37831,USA.
LA  - eng
PT  - Journal Article
DEP - 20140929
PL  - England
TA  - Microsc Microanal
JT  - Microscopy and microanalysis : the official journal of Microscopy Society of 
      America, Microbeam Analysis Society, Microscopical Society of Canada
JID - 9712707
EDAT- 2014/09/30 06:00
MHDA- 2014/09/30 06:01
CRDT- 2014/09/30 06:00
PHST- 2014/09/30 06:00 [entrez]
PHST- 2014/09/30 06:00 [pubmed]
PHST- 2014/09/30 06:01 [medline]
AID - S1431927614013075 [pii]
AID - 10.1017/S1431927614013075 [doi]
PST - ppublish
SO  - Microsc Microanal. 2014 Dec;20(6):1791-7. doi: 10.1017/S1431927614013075. Epub 
      2014 Sep 29.