Dielectric spectroscopy and magnetometry investigation of Gd-doped strontium titanate ceramics

Structure, Microstructure, and Dielectric Response of Polycrystalline Sr1-xZnxTiO3 Thin Films

“…A similar variation of the permittivity with dopant content originated from the offcentrality of smaller ions on large Sr sites was reported for Ca-, Bi-, Gd-, Dy-, and Y-substituted ST systems [12,15,18,19,[21][22][23]. At low content of the off-central ions, they induce independent polar dipoles, which can enhance the dielectric permittivity of the material.…”

“…In the case of Sr 1-x Ca x TiO 3 , the permittivity was reported to be the highest for Ca content x = 0.0107, further dropping with x increase toward 0.12 [12]. For Sr 1-1.5x Bi x TiO 3 ceramics, the highest permittivity was observed at Bi content x = 0.0067 [15], while for Sr 1-1.5x M x TiO 3 ceramics with M = Gd, Dy, or Y, the highest permittivity was also observed for x as low as 0.01 [19,21,23]. Therefore, the dielectric behaviour of Sr 1-x Zn x TiO 3 films of this study is in the line with the permittivity variations of other ST-based systems.…”

“…In the case of ST thin films, these changes can be significantly enhanced, resulting e.g., in ferroelectricity induced at room temperature in epitaxial ST films by DyScO 3 substrate lattice misfit strain [9]. In addition to the strain [5,9,10], dopants can also induce a variety of phases, ranging from dipolar glass and relaxor to ferroelectric, at isovalent substitution for Sr 2+ by Ba 2+ [6,11], Pb 2+ [6], Ca 2+ [12,13], and Mn 2+ ions [8,14] as well as at heterovalent substitution for Sr 2+ by Bi 3+ [7,[15][16][17], Y 3+ [18][19][20], Dy 3+ [21] and Gd 3+ ions [22,23]. We would wish to note here, that since the perovskite structure of SrTiO 3 is tolerant to substitutional dopants, whereas interstitial doping is not likely to occur in SrTiO 3 [24], doping in this work means ionic substitution.…”

Simultaneously Achieving Colossal Permittivity, Ultralow Dielectric Loss Tangent, and High Insulation Resistivity in Er-Doped SrTiO3 Ceramics via Oxygen Vacancy Regulation

“…It has excellent basic properties such as a ∼3.2 eV band gap, high permittivity, and low dielectric loss. Therefore, it becomes an excellent candidate for materials with colossal permittivity and low dielectric loss. ,− Recently, it has been reported that several elements (La 3+ , Nb 5+ , Zr 4+ , Ta 5+ , Nb 5+ , and Sm 3+ ) doped SrTiO 3 ceramics, which then achieved CP and low dielectric loss. ,,− It can be seen that there is much research on doped A-site or B-site elements, while only little research concerns amphoteric elements. Some studies have shown that the oxygen vacancy (V O •• ) can greatly affect the physical properties of SrTiO 3 , such as electrical and optical properties, and can even cause the transformation of metal insulators and superconductivity.…”

Ferroelectric order driven Eu3+ photoluminescence in BaZrxTi1−xO3 perovskite

“…12) of Eu 3+ (1.226 Å) is much smaller than that of Ba 2+ (1.610 Å) and, consequently, the lanthanide ion is over-coordinated when it is positioned at the Ba site and the possibility of occupying a lower symmetry site has to be considered. Very recent investigations including careful crystal structure determination from synchrotron X-ray diffraction data and first-principle calculations on Gd- and Dy-doped BaTiO 3 52,53 as well as the study of dielectric relaxations in Gd- and Dy-doped SrTiO 3 54,55 have provided some evidence about the off-center displacement of trivalent lanthanide ions with average size at A-site of these perovskites.…”