The following formula was used

The following formula was used to assess the values of the magnetic moments in both compounds: where μ (in Bohr magnetons μB) is the magnetic moment; M is the magnetization; B (in Oe) is the applied measuring magnetic field; kB is the Boltzmann constant, N is the number of magnetic atoms per unit of volume. The slopes of the M–1(T) dependences (lines 2 in Fig. 2) were determined for the experimental curves 1 in the high-temperature region; upon substitution into formula (2), the magnetic moments for both compounds were calculated. They were as follows: μ1=2.47(1) μB/Mn and μ2=2.82(1) μB/Mn for LSMO-0.125 and LSMO-0.07, respectively.
Acknowledgment This study was supported by the Russian Science Foundation (Project no. 14-22-00136 “Structure and properties of self-organized and composite mesostructured ferroelectrics and piezoelectrics and multifunctional materials”).
Introduction The solid solution of the PbFe2/3W1/3O3 type (PFW for short) is a relaxor ferroelectric with the perovskite structure with non-isovalent substitution of ions at B site. Ref. [1] was the first to synthesize PFW and analyze its structure by X-ray crystallography. That study also determined the Curie temperature for this THZ1 manufacturer (183K) and suggested the presence of antiferromagnetic properties (along with ferroelectric ones) associated with the presence of Fe3+ ions. Later, Refs. [2,3] found that the long-range antiferromagnetic order developed in PFW under temperatures below 363K (the Néel temperature). Ref. [4] proved that PFW possessed relaxor properties, i.e., that the temperature of the dielectric permittivity peak ε depended on the frequency and the presence of the frequency dispersion ε(ω,Т) below the temperature of the peak ε. Ref. [5] established that adding the PbTiO3 (PT) ferroelectric to PFW allowed to obtain a continuous series of solid (1–x)PFW–(x)PT solutions. A phase diagram was constructed on the basis of these studies, indicating that the Néel temperature decreased with an increase of the PT concentration, while the Curie temperature increased. This diagram also included a region in PFW–PT where the ferroelectric and the antiferromagnetic states coexisted. The solid solutions in question were first studied by X-ray crystallography in [4] at room temperature for the values x = 0; 0.10; 0.20; 0.25; 0.30; 0.325; 0.35; 0.40; 0.60 and 0.80. The analysis of the diffraction patterns revealed that the sample exhibited a cubic phase at < x <0.25. The dielectric spectroscopy results obtained in [4] revealed typical relaxor properties, such as the frequency dispersion of the dielectric permittivity peak and the failure of the Curie–Weiss law, in the (x, T) coordinates near the (0, 190) and (0.1, 220) points where the transition from cubic to pseudocubic phase occurs (Fig. 1). The frequency dependence of the dielectric permittivity peak weakens substantially with an increase of x along the interphase boundary (between the cubic phase and any other), but at high temperatures, there are marked deviations from the Curie–Weiss law. The solution behaves like a normal ferroelectric near the (0.6; 500) point and above. More detailed (with respect to the lead titanate concentration) studies at room temperature were conducted in [6] for solid (1–x)PFW–(x)PT solutions at x = 0.0; 0.10; 0.15; 0.20; 0.25; 0.27; 0.30; 0.31; 0.32; 0.35; 0.37; 0.40; 0.50 and 1.0. It was established that the cubic and the tetragonal phases coexisted in the 0.20 < x <0.37 region. The dependence for the percentage of these phases depending on x was also obtained. Ref. [4] constructed a phase diagram for (1–x)Pb(Fe2/3W1/3O3)–(x)PbTiO3 based on the data obtained by differential scanning calorimetry and by measuring the dielectric permittivity (see Fig. 1). It can be clearly seen that the temperature of the transition from the cubic phase (space group (SG) ) into the pseudocubic one with the R3m symmetry or the tetragonal one (SG P4mm) increases linearly with an increase of x. The pseudocubic phase is cubic with rhombohedral distortions of less than 0.01° [6]; it is in this phase that the compound exhibits relaxor properties. The tetragonal phase is normal ferroelectric. The region of the PT concentrations 0.25 < x <0.35 where different phases coexist is called the morphotropic phase boundary (MPB). Compounds of this type are known to exhibit the most interesting macroscopic properties, such as high values of dielectric permittivity, piezoelectric response, electrostriction, etc., exactly in the MPB region.