Universal critical scaling of ac-vortex-transport properties in superconducting Y-Ba-Cu-O single crystals: From 1 to 90 kOe

Transport measurements showing universal critical scaling behavior of the ac conductivity in superconducting twinned Y-Ba-Cu-O single crystals provide unambiguous evidence for a second-order vortex-solid melting transition. Critical exponents are found to be consistent for fields ranging from 1 to 90 kOe as well as with those found from dc-transport measurements. Additionally, the universal functions for both the resistivity amplitude and phase are identified. © 1993 The American Physical Society.