Preparation of high-purity Tl-based ``1223'' superconductor phase by modified Pechini process in water solution
Abstract
Because of the mixed metal valance state of thallium in a Tl-based superconductor, a nearly single ``1223'' phase can be readily prepared by a modified Pechini method (US Patent 3 330 697). Tl2O3 and other metal nitrates are dissolved in an aqueous solution plus a certain amount of oxalic acid for chelating the metal cations. The desired phase shows zero resistance at 114 K and the phase purity is identified by x-ray diffraction. Characteristics of superconductivity also are evidenced by the Meissner effect. The preparation technique is considered valuable to purify multiphase superconductors for mass production.
- Publication:
-
Applied Physics Letters
- Pub Date:
- May 1991
- DOI:
- 10.1063/1.104865
- Bibcode:
- 1991ApPhL..58.2435C
- Keywords:
-
- Diamagnetism;
- Electrical Resistance;
- High Temperature Superconductors;
- Magnetization;
- Mixed Oxides;
- Thallium Compounds;
- Calcium Oxides;
- Cations;
- Copper Oxides;
- Nitrates;
- Strontium Compounds;
- X Ray Diffraction;
- Solid-State Physics