Brittleness of high T c Bi0.7Pb0.3SrCaCu1.8Ox crystal and glass

Abstract
We suggest a convenient and standard evaluation method of brittleness for high Tc Bi0.7Pb0.3SrCaCu1.8Ox. The crystal oxides are ductile, whereas the liquid‐quenched glassy oxide is brittle. The high Tcoff (111.7 K) sample, annealed for 12 h at 1120 K, is ductile.