Phase diagram of the PrFeAsO${}_{1-x}$F${}_x$ superconductor

Abstract

The electronic phase diagram of PrFeAsO${}_{1-x}$F${}_x$ (0$\le$x$\le$0.225) has been determined using synchrotron X-ray powder diffraction, magnetization and resistivity measurements. The structural transition temperature is suppressed from 154 K to $\approx$120 K and the magnetic phase transitions of both iron and praseodymium ions are completely suppressed by x$\approx$0.08 fluorine doping, coinciding with the emergence of superconductivity. The optimal doping is x$\approx$0.15 when T${}_C$=47 K, while the maximum solubility of fluorine in PrFeAsO${}_{1-x}$F${}_x$ is reached around x=0.22. The structural, magnetic and superconducting phase diagram is presented.

6 pages, 6 figures