Measure of the magnitude of Young's modulus in whisker-like samples of the Bi-based high-T c materials Bi 2Sr 2CaCu 2O x and Bi 2Sr 2Ca 2Cu 3O x
We have measured Young's modulus in ribbon-like whisker samples of the high- Tc materials: Bi 2Sr 2CaCu 2O x and Bi 2Sr 2Ca 2Cu 3O x. This is the first direct measurement of Young's modulus for whiskers of any of the high Tc materials. We used a stress-strain probe that applies an axial force (uniaxial stress) to the whisker-like sample and simultaneously measures the corresponding sample elongation. The slope of the resulting stress-strain curve yields the magnitude of Young's modulus ( Y). We found these Bi based high- Tc materials to be soft with Y≈20 GPa for Bi 2Sr 2CaCu 2O x and Y≈25 GPa for Bi 2Sr 2Ca 2Cu 3O x.