Multiferroic perovskite (Pb0.845Sm0.08Fe0.035)(Ti0.98Mn0.02)O3 with ferroelectric and weak ferromagnetic properties

Abstract

We have investigated the multiferroic properties of PbTiO3 substituted on the A-site with Sm3+ and Fe2+ magnetic ions. We show that the ceramic material with composition (Pb0.845Sm0.08Fe0.035)(Ti0.98Mn0.02)O3 has a spontaneous ferroelectric polarization of about 14 μC/cm2 and weak ferromagnetism (remanent magnetization ∼2.3 emu/g) which persists even at room temperature. The dielectric constant is 190, tan δ ∼ 0.005, and the piezoelectric g33 constant is 25 mV × m/N. Temperature dependence of dielectric permittivity shows a strong anomaly at 662 K, at the paraelectric-ferroelectric transition, and a broader anomaly below 140 K where magnetization also increases, probably due to magnetoelectric coupling between ferroelectric and magnetic states.

Multiferroic properties and magnetoelectric coupling in Fe/Co co-doped Bi3.25La0.75Ti3O12 ceramics

“…Various attempts have been made to synthesize room temperature multiferroic materials, among which doping magnetic species into ferroelectric materials is probably one of the most effective ways. [5][6][7][8][9][10][11][12][13][14][15][16][17] Ferromagnetism is successfully introduced into BaTiO 3 and PbTiO 3 , conventional ferroelectric materials with a simple perovskite structure, by doping magnetic ions (such as Fe or Mn) at the Ti-sites, however, the ferroelectricity is suppressed simultaneously due to the decreased structural distortion and the enhanced leakage current. [5][6][7][8][9][10] Recently, the multilayer-structured Bi 4+n Ti 3 Fe n O 12+3n , viewed as atomic stacking of a three-layered Bi 4 Ti 3 O 12 (BIT, ferroelectrics) and n layer perovskite BiFeO 3 (ferroelectric and antiferromagnetic at room temperature), has attracted great attention.…”

Fabrication of an Fe‐Doped SrTiO3 Photocatalyst with Enhanced Dinitrogen Photofixation Performance

“…However, the slight shifts of (110) and (200) peaks terminated at x = 0.10, suggesting that Fe 3+ ions have very limited solubility in the SrTiO 3 lattice during the present preparation process. It is reasonable by considering that the radii (64.5 pm) of Fe 3+ is much smaller than that (144 pm) of Sr 2+ , which leads to the difficulty in Fe 3+ ions instead of Sr 2+ sites of SrTiO 3 directly, [25][26][27][28] and thus the excessive Fe 3+ ions in Fe x Sr 1-x TiO 3 products with x > 0.10 would generate as α-Fe 2 O 3 to form composites containing α-Fe 2 O 3 and Fedoped SrTiO 3 as shown in Figure 1. From the element compositions determined using X-ray fluorescence (XRF) technique and the relative molar percentages of Fe, Sr, Ti and O atoms listed in Table 1, it can be seen that the Fe-atom molar ratios in Fe x Sr 1-…”

Induction and control of room-temperature ferromagnetism in dilute Fe-doped SrTiO3 ceramics

“…In STF, there are only Ti 4þ vacancies provided for the Fe ions to occupy (Fe 4þ /Fe 3þ ); while in SVTF, the introduction of Sr 2þ vacancies may result in a small amount of Fe ions (Fe 3þ /Fe 2þ ) occupying the Sr-sites; Compared with that in SVTF, the molar ratio of Ti in SFTF is increased, which might lead to more Fe ions (Fe 3þ /Fe 2þ , especially Fe 2þ ) at the Sr-sites. Since the radius of Fe 2þ at the Sr-sites (12 ligand, 1.210 Å ) 21 is smaller than that of Sr 2þ (1.440 Å ), 22 the lattice parameter of SFTF is the minimum among the three samples. While the larger lattice parameter of SVTF might originate from the cation vacancies and the corresponding dangling bonds.…”