Nanocomposites and nanomaterials

Influence of additional synthesis on the phase composition and size of nanopowder lanthanum-strontium La0.6Sr0.4MnO3 manganites
Liedienov N.A.1, 2, Pashchenko A.V.1, 2, 3, Fesych I.V.4, Bychkov K.L.4, Kazanovska K.V.2, Makoed I.I.5, Levchenko G.G.1, 2
1 International Centre of Future Science, State Key Laboratory of Superhard Materials of Jilin University. Qianjin Str., 2699, Changchun-130012, China.
E-mail: nikita.ledenev.ssp@gmail.com
2 Phase Transitions Department, Donetsk Institute for Physics and Engineering named after O. O. Galkin, NASU. Prospect Nauki, 46, Kyiv-03028, Ukraine.
3 Institute of Magnetism NASU and MESU. Acad. Vernadsky Ave., 36-b, Kyiv-03142, Ukraine.
4 Taras Shevchenko National University of Kyiv. Lva Tolstoho Str., 12, Kyiv-01030, Ukraine.
5 Department of Physics, Brest State University. Kosmonavtov Ave., 21, Brest-224016, Belarus.

Nanopowder rare-earth La0.6Sr0.4MnO3 manganites were obtained by sol-gel method from La(NO3)3, Sr(NO3)2 and Mn(NO3)2 nitrates at various temperatures of additional synthesis tsynt = 700, 750, 800, 850 and 900 °C (10 h) in slow heating and cooling regime. The phase composition of the synthesized samples has been controlled by X-ray diffraction analysis using Shimadzu LabX XRD-6000 diffractometer in CuKα radiation (λ = 0.15406 nm, 5 ≤ 2θ ≤ 70°). It has been found out that with increasing tsynt the content of SrCO3 second phase decreases from 5% in nanopowders and at tsynt ≥ 800 °C the samples become completely single-phase. According to X-ray diffraction analysis the average size of the coherent scattering regions D that corresponds to the average dimension of powder nanoparticles has been determined using Sherrer method. The D (D012) size has been calculated using the diffraction peak broadening with angle 2θ ≈ 22.8° (hkl = 012). It has been shown that the average D012 size of nanoparticles increases from 16 nm (700 °C) to 17 nm (750 °C), 20 nm (800 °C), 26 nm (850 °C) and 30 nm (900 °C) with increasing the tsynt temperature.