Diffusion of magnetic flux into Bi2Sr2CaCu2Oy single crystals
Zavaritskii N. V., Zavaritski V. N.
The relaxation of the nonequilibrium magnetization 8M(t) caused by a small change 8H = 0.02-4 Oe <#0 in the external magnetic field HQ = 0.7-10 kOe > HcX has been measured. The results reveal temperature intervals in which the initial part of the 8M (t) curve is governed by a diffusion of magnetic flux into the sample: <5M<xexp( — bt). The model ofa thermally activated flux flow (TAFF) is used along with the curves of b (T) cc ρ (Τ) for the field range studied to determine the heights of the barriers to the motion of vortices: U(H)~ 525-325 K.