Stress corrosion cracking of Bi-2212 thin rods

The flexure strength of Bi2Sr2CaCu2O8+δ thin rods textured by a laser heated floating zone was measured as a function of the environment (air versus water) at room temperature. Loading rates spanning three orders of magnitude (1, 10 and 100 μm/min) were used to explore their susceptibility to the environmental conditions. These mechanical test were completed with electrical characterization (critical current at 77 K and resistivity from 77 to 300 K) of samples submerged in distilled water for different times (0, 12 and 127 h). While Bi2Sr2CaCu2O8+δ has been shown, in previous works, to be unstable during contact with water molecules, the textured rods tested in this work are very inert to the water environment, in mechanical and electrical properties, due to the presence of a very thin (∼100 μm) low textured outer ring formed in the grown process.