Ba3MIIITiMVO9 (MIII = Fe,Ga, Y,Lu; MV = Nb,Ta, Sb) perovskite oxides: Synthesis,structure and dielectric properties |
| |
Authors: | Joby E. Joy Eric Atamanik Rohini Mani Abanti Nag R.M. Tiwari V. Thangadurai J. Gopalakrishnan |
| |
Affiliation: | 1. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India;2. Department of Chemistry, University of Calgary, 2500 University Dr NW, Calgary, Alberta T2N 1N4, Canada |
| |
Abstract: | We describe the synthesis, structures and dielectric properties of new perovskite oxides of the formula, Ba3MIIITiMVO9, for MIII = Fe, Ga, Y, Lu and MV = Nb, Ta, Sb. While MV = Nb and Ta oxides adopt disordered/partially ordered 3C perovskite structures where MIII/Ti/MV metal-oxygen octahedra are corner-connected, the MV = Sb oxides show a distinct preference for the 6H structure, where SbV/TiIV metal-oxygen octahedra share a common face forming (Sb,Ti)O9 dimers that are corner-connected to the MIIIO6 octahedra. The preference of antimony oxides (SbV:4d10) for the 6H structure – which arises from a special SbV–O chemical bonding that tends to avoid linear Sb–O–Sb linkages unlike NbV/TaV:d0 atoms which prefer ~180° Nb/Ta–O–Nb/Ta linkages – is consistent with the crystal chemistry of MV–O oxides in general. The dielectric properties reveal a significant difference among MIII members. All the oxides with the 3C structure excepting those with MIII = Fe show a normal low loss dielectric behaviour with ε = 20–60 in the temperature range 50–400 °C; the MIII = Fe members with this structure (MV = Nb, Ta) display a relaxor-like ferroelectric behaviour with large ε values at frequencies ≤1 MHz (50–500 °C). |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|