Abstract:
© 2019 Elsevier Ltd and Techna Group S.r.l. The structural and magnetic properties of YbMnO 3 and Yb 0.82 Sr 0.18 MnO 3 multiferroics were studied by neutron powder diffraction (NPD), magnetometry and electron spin resonance (ESR) technics in a wide temperature range. Neutron diffraction measurements showed that the substitution of ytterbium ions with strontium ions in hexagonal h - YbMnO 3 (space group P6 3 cm) leads to the destabilization of the crystal structure of the last compound and appearance of the mixture of three phases with different structure: hexagonal phase h - Yb 0.95 Sr 0.05 MnO 3 (space group P6 3 cm), orthorhombic phase o - Yb 0.69 Sr 0.31 MnO 3 (space group Pbnm), hexagonal phase SrMnO 3 (space group P6 3 cm). This fact was proved by the ESR measurements in which a several signals due to the phases of different structure were observed. NPD measurements showed that the magnetic structure of h - Yb 0.95 Sr 0.05 MnO 3 phase is similar to the magnetic structure of the pure h - YbMnO 3 and demonstrate the presence of the antiferromagnetic ordering in the samples. ESR and magnetization measurements of h - YbMnO 3 sample proved the presence of the antiferromagnetic correlations and also they showed the appearance of the ferromagnetically correlated nanoregions.
