ELASTIC-CONSTANTS OF HIGH-TEMPERATURE SUP ERCONDUCTOR YBA2CU3OX

We calculate the defect-free elastic constants of high temperature cer amic superconductor YBa2Cu3Ox from measured elastic constants of bulk YBa2Cu3Ox which contains numerous microcracks and voids. Defect-free e lastic constants represent long-wavelength acoustic phonons and relate to a variety of solid-state-phenomena such as Debye temperature, ther mal expansivity and theoretical strength. By the use of the self-consi stent method or the differential method, we eliminate the effect of ra ndom distribution of microcracks on the elastic constants of YBa2Cu3Ox . The scattered-plane-wave method is also used to eliminate the effect of voids and then obtain the defect-free elastic constants. Numerical calculations are carried out and the influence of the microcracks and the voids on the elastic constants of YBa2Cu3Ox is discussed in detai l.