2024-03-29T05:14:14Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/2104602020-12-13T08:43:30Zcom_10261_99com_10261_5col_10261_352
Synthesis, structure and dielectric properties of a new family of phases, ABC 3 O 11 : A = La, Pr, Nd, Sm, Gd; B = Zr, Hf; C = Ta, Nb
Ros, F.C.
Reeves-McLaren, N.
Masó, Nahum
West, A.R.
Eight new phases with the general formula of ABC O with different rare earth, (Zr, Hf), (Nb, Ta) combinations, have been prepared by solid-state reactions at a temperature range of 1200–1500 °C. The new phases—LaHfTa, LaHfNb, LaZrNb, PrHfTa, NdHfTa, NdHfNb, SmHfTa and GdHfTa—are characterised by X-ray and neutron diffraction data at room temperature and variable frequency impedance measurements. They are isostructural with LaZrTa O which consist of alternating single layers of UO pentagonal bipyramids and octahedra as shown by Rietveld refinement of X-ray and neutron powder diffraction data. Lattice parameters decrease with decreasing size of rare earth element substitution at A-site, and of all, Gd is the smallest rare earth that formed LaZrTa O analogues. Detailed attempts of attained and unattainable LaZrTa O analogues with different temperatures are included in this paper. All phases are highly insulating with temperature-independent bulk permittivities in the range 17 to 50; LaHfNb demonstrates the highest permittivity. Arrhenius plot shows that the activation energies are in the range 0.8 to 1.94 eV.
2020-05-05T10:31:35Z
2020-05-05T10:31:35Z
2018-09-24
2020-05-05T10:31:35Z
artículo
Journal of the Australian Ceramic Society 55: 305-314 (2019)
http://hdl.handle.net/10261/210460
10.1007/s41779-018-0236-x
Publisher's version
http://dx.doi.org/10.1007/s41779-018-0236-x
Sí
openAccess
Springer Nature