57Fe-enriched perovskites M(Fe0.5Nb0.5)O3 (M – Pb, Ba) studied by Mössbauer spectroscopy, NMR and XRD in the wide temperature range 4.2–533 K

0497826 - ÚACH 2020 RIV NL eng J - Journal Article
Kmjec, T. - Adamec, M. - Kubániová, D. - Plocek, Jiří - Dopita, M. - Česnek, M. - Chlan, V. - Bednarčík, J. - Závěta, K. - Maryško, Miroslav - Kohout, J.
57Fe-enriched perovskites M(Fe0.5Nb0.5)O3 (M – Pb, Ba) studied by Mössbauer spectroscopy, NMR and XRD in the wide temperature range 4.2–533 K.
Journal of Magnetism and Magnetic Materials. Roč. 475, APR (2019), s. 334-344. ISSN 0304-8853. E-ISSN 1873-4766.
[Joint European Magnetic Symposia /9./ JEMS 2018. Mainz, 03.09.2018-07.09.2018]
Institutional support: RVO:61388980 ; RVO:68378271
Keywords : Hyperfine interactions * Lead/barium-iron niobate * Magnetic ordering * Multiferroics * Mössbauer spectroscopy * NMR * Transition temperature * XRD
OECD category: Inorganic and nuclear chemistry; Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)
Impact factor: 2.717, year: 2019
Method of publishing: Open access with time embargo

The 57Fe enriched almost single-phase perovskites Pb(Fe0.5Nb0.5)O3 (PFN) and Ba(Fe0.5Nb0.5)O3 (BFN), prepared by a ceramic method (solid-state synthesis), were studied by Mössbauer spectroscopy, nuclear magnetic resonance (NMR), conventional and synchrotron X-ray powder diffraction (XRD). The temperature dependences of hyperfine and structural parameters of PFN, BFN from 4.2 K to temperatures above ferroelectric ordering of PFN (TS ∼ 375 K), with attention to the values of magnetic and structural transitions, were obtained. The antiferromagnetic magnetic ordering transitions were found under the Néel temperatures TN ∼ 167(3) K and 32(2) K for BFN and PFN, respectively. The spin-glass transition was at TG ∼ 10(3) K and 20(5) K for BFN and PFN, respectively. In PFN sample a small change of structural parameters around TN and structural change from trigonal to cubic structure at T ∼ 400 K was observed by XRD. The temperature dependence of XRD shows stable cubic structure in the temperature range from 4.2 K to 530 K for BFN. From Mössbauer and NMR spectroscopies it is found that both structures have perturbed environments for Nb and Fe. However, in case of PFN the low values of transferred hyperfine fields disfavour random Fe/Nb arrangement and allow proposing a picture of Fe/Nb arrangement.
Permanent Link: http://hdl.handle.net/11104/0293949