This paper reported the synthesis of Ho-doped SBN (SrBi2−xHoxNb2O9: x = 0 and 0.4) by a co-precipitation method and investigated the synthesized material with X-ray diffraction analyses, infrared spectroscopy, and electrical measurements. The results show that the Ho-doped SBN has low loss values at higher frequencies and the flattening of dielectric constant which are very desirable in nonvolatile ferroelectric random access memory applications.

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This paper presents a study of the structure and dielectric properties of Eu-doped SrBi2Nb2O9 ceramics prepared by co-precipitation route and sintered at 850?C. The materials were examined using XRD and FTIR methods. XRD data indicated the formation of well crystallized structure of the pure and doped SrBi2Nb2O9, without the presence of undesirable phases. FTIR spectra do not bring a significant shift in the band positions. Moreover, the AC conductivity, dielectric constant and dielectric loss of the ceramics were determined through the frequency range [50 kHz-1MHz]. In particular, the dielectric constant (??) and dielectric losses (tan ?) of the SrBi2Nb2O9 and SrBi1.6Eu0.4Nb2O9 ceramics were measured as a function of temperature at various frequencies.

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

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