Hydrothermal Synthesis, Crystal Structure, and Superconductivity of a Double-Perovskite Bi Oxide

Abstract

Double-perovskite Bi oxides are a new series of superconducting materials, and their crystal structure and superconducting properties are under investigation. In this paper, we describe the synthesis and characterization of a new double-perovskite material that has an increased superconductive transition temperature of 31.5 K. The structure of the material was examined using powder neutron diffraction (ND), synchrotron X-ray diffraction (SXRD), and transmission electron microscopy (TEM). Rietveld refinement of the sample based on ND and SXRD data confirmed an A-site-ordered (K1.00)­(Ba1.00)3­(Bi0.89Na0.11)4O12 double-perovskite-type structure with the space group Im3̅m (No. 229). This structural analysis revealed the incorporation of Na with Bi in the structure and a bent bond between (Na, Bi)–O–(Na, Bi). TEM analyses also confirmed a cubic double-perovskite structure. This hydrothermally synthesized compound exhibited a large shielding volume fraction, exceeding 100%, with onset of superconductivity at ∼31.5 K. Its electrical resistivity dropped near onset at ∼28 K, and zero resistivity was confirmed below 13 K. The calculated band structure revealed that the metallicity of the compound and the flatness of the conduction bands near the Fermi level (E F) are important for the appearance of superconductivity.

Perovskite Oxides Prepared by Hydrothermal and Solvothermal Synthesis: A Review of Crystallisation, Chemistry, and Compositions

“…For example, the material (K1.00)(Ba1.00)3(Bi0.89Na0.11)4O12 shows ordering of the A-site K and Ba, while the B-site Bi and Na share the same crystallographic position to give a body-centred cubic unit cell with edge length double the conventional perovskite structure, Figure 22. [243] In the case of (Ba0.62K0.38)(Bi0.92Mg0.08)O3, the A-site and Bsite cations show no ordering, [244] and the metallic nature of the material was verified using first-principles calculations. [245] For several of these materials the onset of superconductivity was measured by detecting the characteristic diamagnetism in a polycrystalline powder, but also from resistivity measurements of pressed pellets.…”

Hydrothermal synthesis and crystal structure of a novel double-perovskite-type bismuth oxide with 3 : 1 ordering at the B-site

“…3 shows a comparative graphical representation of the unit cell volume versus the sum of the ionic radii of the A and B cations of Ba 4 Bi 3 NaO 12 and the previously reported perovskitetype superconducting and semiconducting bismuth oxides. [3][4][5][6][7]10,11,13,14,30,43,46 The novel compound (blue circle) exhibited an almost linear relationship with the semiconducting bismuth oxides (red circle). It was also located near the region of some superconducting bismuth oxides (green circle); however, this compound may not be a superconductor because of the presence of only Bi 5+ at the B-site.…”

“…4,5 Recently, a variety of perovskite-type bismuth oxides have been synthesized by a low-temperature hydrothermal method using NaBiO 3 ÁnH 2 O as the starting material. [4][5][6][7][8][9] In this method, the partial substitution of A-and B-site cations significantly affects the structure and various properties of the compounds. Monoclinic BaBiO 3 was found to be semiconducting with a distorted perovskite-type structure, and the BiO 6 octahedra were tilted at a lower angle.…”

“…28,29,[34][35][36] Moreover, hydrothermally prepared single-and double-perovskite-type bismuth oxides exhibited superconductivity with relatively high transition temperatures. 4,6,7,13,30 Therefore, based on the exploration of more compounds, a novel perovskitetype bismuth oxide was developed via a facile hydrothermal reaction using NaBiO 3 ÁnH 2 O as the starting material. This study discusses the crystal structure, thermal stability, photocatalytic activity, and electronic band structure of the newly synthesized bismuth oxide.…”

An electrochemically reversible lattice with redox active A-sites of double perovskite oxide nanosheets to reinforce oxygen electrocatalysis

“…[9][10][11][12][13] While 4d or 5d transition metal based layered perovskite structures of Dion-Jacobson, Ruddlesden-Popper and Aurivillius phases are obtained by the exfoliation method, 9 the exploration of other 2D perovskite oxide systems with strongly correlated d-orbital electrons is impeded by the expensive physical techniques. Equipped with exotic properties such as high oxygen mobility, extensive stoichiometric range, redox exibility and thermal stability, the applications of perovskites span a rich spectrum of high temperature superconductivity, 14 colossal magnetoresistance, 15,16 ferroelectricity, 17 high dielectric constant, 18 sensing, 1 fuel cells, 19,20 electrocatalytic conversion, 21,22 and storage. 23,24 Planar manifestation of this outstanding class of complex oxides, especially with rst row transition metals, by avant-garde methods is expected to imbibe state-of-the-art fundamental properties leading to newer functionalities and devices.…”