MAGNETOSTRICTION OF A SUPERCONDUCTOR - RESULTS FROM THE CRITICAL-STATE MODEL

In many cases, the critical-state theory can be treated as a sufficien tly accurate approximation for the modeling of the magnetic properties of superconductors. In the present work, the magnetostrictive hystere sis is computed for a quite general case of the modified Kim-Anderson model. The results obtained reproduce many features of the giant magne tostriction (butterfly-shaped curves) reported in the literature for m easurements made on single-crystal samples of the high-temperature sup erconductor Bi2Sr2CaCu2O8. It is shown that the addition of a contribu tion to the magnetostriction in the superconducting state which is of similar origin as in the normal state, offers a broader phenomenologic al interpretation of the complex magnetostriction hysteresis found in such heavy-fermion compounds as UPt3, URu2Si2, or UBe13. (C) 1996 Amer ican Institute of Physics.