Grain boundaries in high temperature superconducting ceramics

Dislocations and Grain Boundaries in Ceramics and Metals

This paper is offered as a tribute to the late Gareth Thomas and the celebration of his career using transmission electron microscopy. His early work on dislocations and twin boundaries in metals suggested indirect methods for determining the stacking-fault energies (SFEs) of Al [1] and Ni [2] and subsequently examined questions on how the measured values of SFEs of copper alloys change when th...

Chemical stability of grain boundaries in β-tricalcium phosphate ceramics

Intercalated Nanocomposites Based on High-Temperature Superconducting Ceramics and Their Properties

High temperature superconducting (SC) nanocomposites based on SC ceramics and various polymeric binders were prepared. Regardless of the size of the ceramics’ grains, the increase of their amount leads to an increase of resistance to rupture and modulus and a decrease in limiting deformation, whereas an increase in the average ceramic grain size worsens resistance properties. The SC, thermo-che...

New buffer layer for high-temperature superconducting ceramics on sapphire: LaBa2Cu3Oy/Ag bilayers

Sapphire (a-A1203) is a desirable substrate for the growth of superconducting thin films due to its low dielectric constant and the extensive interest on silicon on sapphire technology. Unfortunately there exists a strong chemical interaction between sapphire and REBa,CusO,, ( RE123 ) ceramics’-3 which complicates the growth of high-quality-thin-film ceramic superconductors. Several reports on ...

Mechanisms for enhanced supercurrent across meandered grain boundaries in high-temperature superconductors

It has been well established that the critical current density Jc across grain boundaries GBs in high-temperature superconductors decreases exponentially with misorientation angle beyond 2° –3°. This rapid decrease is due to a suppression of the superconducting order parameter at the grain boundary, giving rise to weakly pinned Abrikosov-Josephson AJ vortices. Here we show that if the GB plane ...