Peculiarities of $$^{57}$$ 57 Fe NMR Spectrum in Micro- and Nanocrystalline Europium Orthoferrites

  • PDF / 1,475,937 Bytes
  • 10 Pages / 439.37 x 666.142 pts Page_size
  • 89 Downloads / 182 Views

DOWNLOAD

REPORT


Applied Magnetic Resonance

ORIGINAL PAPER

Peculiarities of 57 Fe NMR Spectrum in Micro‑ and Nanocrystalline Europium Orthoferrites Anastasia Sklyarova1   · Vadim I. Popkov2 · Ivan V. Pleshakov3 · Vladimir V. Matveev4 · Helena Štěpánková1 · Vojtěch Chlan1 Received: 8 May 2020 / Revised: 3 July 2020 © Springer-Verlag GmbH Austria, part of Springer Nature 2020

Abstract NMR spectra of 57 Fe dispersed europium orthoferrite in powder samples with micro- and nanocrystalline particles were studied for the first time. The material was synthesized by glycine–nitrate combustion, which allowed to obtain the specimens with granular diameters of 60  nm (nano-EuFeO3 ) and 1.5 μm (micro-EuFeO3 ). It was found out that the spectra are more complex than could be expected for a compound with a single crystallographic position of Fe3+ ions, and it was also identified that there is a noticeable difference in samples with different fineness. Assumptions about the possible physical nature of the observed effects are made.

1 Introduction Rare-earth orthoferrites in whole and EuFeO3 , in particular, are subjected to a relentless interest due to their promising properties for practical use. Being potential materials for the finding of multiferroic behavior, these ferrites undergo attention concerning their synthesis, modifications and study of their properties. Although EuFeO3 is known already quite a long time and this material in the bulk state has been well studied, since the beginning of nanomaterials era, the interest to this substance has been renewed due to the potential application of its nanocrystals in photocatalytic materials, memory devices, gas sensors, etc. [1–4]. It would seem that the properties of EuFeO3 are well known but there is no clear information about the magnetic moments ordering and how it changes in the different material state (bulk, nano, thin film). Previous research results show that * Anastasia Sklyarova [email protected] 1

Faculty of Mathematics and Physics, Charles University, 18000 Prague 8, Czech Republic

2

Hydrogen Energy Laboratory, Ioffe Institute, Saint Petersburg 194021, Russia

3

Laboratory of Quantum Electronics, Ioffe Institute, Saint Petersburg 194021, Russia

4

Faculty of Physics, Saint Petersburg State University, Peterhof, Saint Petersburg 198504, Russia



13

Vol.:(0123456789)



A. Sklyarova et al.

physical and chemical properties of ferrites may depend on the preparation route used for obtaining these materials, as it was shown for YFeO3 , where the spin reorientation transition was found in the hydrothermally prepared samples [5]. Moreover, some deviations on temperature curves of the magnetic susceptibility have been found for LuFeO3 and EuFeO3 , prepared by hydrothermal method, which may indicate the existence of spin reorientation in these samples too [6], although the investigation of similar substances, prepared by other methods, contradicts the presence of spontaneous spin reorientation transition in these type of materials [7]. Concerning the magnetic structure, ABO3 m