Superconducting Double Perovskite Bismuth Oxide Prepared by a Low‐Temperature Hydrothermal Reaction

Abstract

Perovskite‐type structures (ABO3) have received significant attention because of their crystallographic aspects and physical properties, but there has been no clear evidence of a superconductor with a double‐perovskite‐type structure, whose different elements occupy A and/or B sites in ordered ways. In this report, hydrothermal synthesis at 220 °C produced a new superconductor with an A‐site‐ordered double perovskite structure, (Na0.25K0.45)(Ba1.00)3(Bi1.00)4O12, with a maximum Tc of about 27 K.

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.…”

“…10,11 Notably, in the case of tetragonal symmetry, the possible distortion may result from the octahedral rotations of the Ba 1Àx K x BiO 3 (BKBO) system. 12 Rubel et al 6 synthesized a new A-site-ordered double-perovskite-type bismuth oxide (Na 0.25 K 0.45 )(Ba 1.00 ) 3 (Bi 1.00 ) 4 O 12 , which exhibited a 3 : 1 ordering of Ba:(Na,K) cations at the A-site. In the doubleperovskite-type structure of (Ba 0.54 K 0.46 ) 4 Bi 4 O 12 , the A-sites are occupied by the K + /Ba 2+ ions, and the B-sites are occupied by bismuth ions in a mixed valence state (Bi 5+ /Bi 3+ ) with BiO 6 octahedra.…”

“…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.…”

Studying Impact of Different Precipitating Agents on Crystal Structure, Morphology and Photocatalytic Activity of Bismuth Oxide

“…In the case of supported oxide catalyst the deposition method also plays an important role in the performance of the catalyst. The deposition method determines whether the catalyst is uniformly distributed on the support or accumulation of the oxide takes place on the areas of the support [10,11,12]. Therefore, various methods have been reported for synthesis Bi2O3 that include hydrothermal [13], direct precipitation [14][15][16][17][18][19], microwave [6,20], solution combustion [21,22], and sol gel [1].…”