skip to main content

Title: The magnetic and neutron diffraction studies of La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles prepared via molten salt synthesis

Series of single-phase La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles (x=0.25−0.47) with the size of about 50 nm was prepared in molten NaNO{sub 2}. TEM evidenced well dispersed particles that are not interconnected by sintering bridges in contrast to traditional products. Interestingly, some reduction of the perovskite cell volume, particularly at higher Sr-contents, was detected by XRD. Moreover, reduced magnetization and decreased Curie temperature in comparison to sol–gel samples were observed. Neutron diffraction analysis of the as-prepared nanoparticles and several comparative samples with x=0.37 indicated that the anomalous behavior of studied particles probably originate in the overdoped outer shell. The overdoping might result from both the surface oxygen chemisorption and from an increased Sr concentration in the shell. By all means, the overdoping would lead to compressive surface stress, driving the x=0.37 ground state toward a mixture of FM and A-type AFM ordering as observed by neutron diffraction. - Graphical abstract: La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles with the size of about 50 nm were prepared by newly established method in molten NaNO{sub 2}. TEM proved the formation of well-separated particles without sintering bridges, the major advantage over traditional preparation methods. - Highlights: • Series of La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles was preparedmore » by novel method in NaNO{sub 2} melt. • Lower magnetization and Curie temperature in comparison to sol–gel nanoparticles was observed. • Overdoping of outer shell was indicated by neutron diffraction and cerimetric titration. • Overdoping shifts La{sub 0.37}Sr{sub 0.63}MnO{sub 3} ground state to a mixture of FM and A-type AFM ordering.« less
Authors:
 [1] ;  [2] ;  [1] ;  [2] ; ; ; ;  [3] ;  [4]
  1. Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic)
  2. (Czech Republic)
  3. Institute of Physics, AS CR, Cukrovarnická 10, 162 00 Praha 6 (Czech Republic)
  4. Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Břehová 7, 115 19 Praha 1 (Czech Republic)
Publication Date:
OSTI Identifier:
22443520
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 221; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMIC FORCE MICROSCOPY; CHEMISORPTION; CURIE POINT; GROUND STATES; MAGNETIZATION; MIXTURES; MOLTEN SALTS; NANOPARTICLES; NEUTRON DIFFRACTION; NITRITES; OXYGEN; PEROVSKITE; SINTERING; SODIUM COMPOUNDS; STRESSES; SYNTHESIS; TITRATION; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION