Correlated pressure effects on the structure and superconductivity ofLaFeAsO0.9F0.1

We have studied the structural and superconducting properties of the compound ${\text{LaFeAsO}}_{0.9}{\text{F}}_{0.1}$ under pressures up to 32 GPa using synchrotron radiation and diamond anvil cells. We obtain an ambient pressure bulk modulus ${K}_{0}=78(2)\text{ }\text{GPa}$ compressibility comparable to some cuprates. At high pressures, the sample is in the overdoped region, with a linear decrease with pressure variation of the superconducting transition temperature.