Fluctuation conductivity of a c-axis-oriented ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{\mathit{y}}$ film prepared by chemical vapor deposition

The magnetoresistance of a highly c-axis-oriented chemical-vapor-deposition film of ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathit{y}}$ was measured in the temperature range ${\mathit{T}}_{\mathit{c}}$≲T≤103 K for both the H∥c axis and H⊥c axis. The analysis has been done on the basis of the superconducting fluctuation theory for the clean limit, and a good fit has been obtained for the temperature and the magnetic-field dependences of the magnetoconductance in the cases of the H∥c axis and H⊥c axis. The results indicated that all of both orbital and Zeeman effects of the Aslamasov-Larkin and the Maki-Thompson terms contributed to the fluctuation conductivity. The superconducting coherence lengths were estimated to be ${\xi }_{\mathit{a}\mathit{b}}$(0)=11.5 Å and ${\xi }_{\mathit{c}}$(0)=3.2 Å in addition to the phase breaking time of the carrier ${\mathrm{\tau }}_{\mathrm{\phi }}$=8×${10}^{\mathrm{-}14}$ sec at 100 K.