Experimental test of the T2 law for the Hall angle from Tc to 500 K in oxygen-reduced YBa2Cu3O6+x crystals.

Abstract

In both 90-K'' and 60-K'' YBa[sub 2]Cu[sub 3]O[sub 6+[ital x]] crystals, we find that the [ital T][sup 2] law for the Hall angle, measured with field [bold H][parallel][bold c], remains valid for temperatures [ital T] between [ital T][sub [ital c]] and 500 K. The persistence of power-law behavior over this wide range is not affected by oxygen reduction. In contrast to this anomalous behavior, the Hall coefficient observed with [bold H][perpendicular][bold c] is [ital negative] [ital and] [ital temperature] [ital independent]. Measurements of the in-plane resistivity [rho][sub [ital x][ital x]] to 500 K disclose the existence of a kink temperature [ital T][sub [ital K]] ([similar to]320 K) that separates a high-temperature power-law regime from a low-temperature region in which [rho][sub [ital x][ital x]] displays significant curvature.