Magnetic studies are performed on randomly oriented and aligned polycrystalline samples of HgBa2CaCu2O6+x (Hg-1212) and HgBa2CaCu2O8+x (Hg-1223). The measurements of magnetic hysterisis and magnetic relaxation confirmed the existence of a strong surface barrier. The decay of the critical current density Jc with temperature is much slower than the decay of their single-layered counterpart, Hg-1201. Measurements of aligned Hg-1212 revealed that the dependence of Jc on field orientation is relatively weak and the irreversible area in the H-T plane is much wider than other high temperature superconductors. Although neutron irradiation only enhances the critical current values moderately and severely suppresses the surface pinning, neutron irradiation improves all of the magnetic properties mentioned above, and at T = 100 K, the hysteresis loop remains open up to H = 6 kG.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering