Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries

Details Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries

2005-05-23

arxiv.org/abs/cond-mat/0505568v1

Nature Materials, Published online: 22 May 2005; doi:10.1038/nmat1394

Physics

Condensed Matter

Materials Science

19 pages, 6 Figures

Scientific paper

10.1038/nmat1394

Practical high temperature superconductors must be textured to minimize the reduction of the critical current density $J_{gb}$ at misoriented grain boundaries. Partial substitution of Ca for Y in $YBa_2Cu_3O_{7-\delta}$ has shown significant improvement in $J_{gb}$ but the mechanisms are still not well understood. Here we report atomic-scale, structural and analytical electron microscopy combined with transport measurements on $7^{\circ}$ $[001]$-tilt $Y_{0.7}Ca_{0.3}Ba_2Cu_3O_{7-\delta}$ and $YBa_2Cu_3O_{7-\delta}$ grain boundaries, where the dislocation cores are well separated. We show that the enhanced carrier density, higher $J_{gb}$ and weaker superconductivity depression at the Ca-doped boundary result from a strong, non-monotonic Ca segregation and structural rearrangements on a scale of ~1 nm near the dislocation cores. We propose a model of the formation of $Ca^{2+}$ solute atmospheres in the strain and electric fields of the grain boundary and show that Ca doping expands the dislocation cores yet enhances $J_{gb}$ by improving the screening and local hole concentration.

Affiliated with

Also associated with

No associations

Rating

Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YBa_2Cu_3O_{7-δ}$ grain boundaries will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-72425