Compositions for melt processing high temperature superconductor

US5872081A · kind A · utility

Assignees

• General Atomics · US
• SHIMABUN CORPORATION · JP

Inventor

• Lawrence D. Woolf · Saint Helier, JE

Key dates

• Filing date: Apr 7, 1995
• Grant date: Feb 16, 1999
• Expiry date: Apr 7, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N60/0268

Abstract

A melt processing method for bulk or thick film fabrication of RE123 superconductor material includes the steps of using Nd in the RE123 to increase the recrystallization speed of the RE123, and using a heavy rare earth in the RE123 to establish the peritectic melting point of the RE123 somewhere below the melting point of silver. Within these requirements, the method essentially includes heating the RE123 above its peritectic melting point, and then cooling the resultant decomposed material to recrystallize the RE123. The heavy rare earths to be used for lowering the RE123 peritectic melting temperature include Lu, Yb, Tm or Er or mixtures thereof. The addition of RE211, silver and the use of a low oxygen partial pressure also contribute to a lowering of the melting point of the RE123. When using Nd to accelerate the processing time, the RE123 can include a first component of Nd.sub.1-z R.sub.z 123 and a second component of Nd.sub.1-y R.sub.y 211. For these components, R is one of the heavy rare earths, z is between 0 and approximately 0.9, and y is between 0 and approximately 0.9.