The anisotropic thermopower of ${\mathrm{Tl}}_2$${\mathrm{Ba}}_2$${\mathrm{CuO}}_6$ single crystals has been measured between 80 and 300 K. Both ${\mathit{S}}_{\mathit{a}\mathit{b}}$ and ${\mathit{S}}_{\mathit{c}}$ vary linearly with temperature, but their slope signs are opposite. The results confirm again an earlier inference that the linear dependence of ${\mathit{S}}_{\mathit{a}\mathit{b}}$ on T with a negative slope is quite common to high-${\mathit{T}}_{\mathit{c}}$ superconductors.

• Received 19 October 1992

DOI:https://doi.org/10.1103/PhysRevB.47.8324