  Electrical resistivity and magnetic susceptibility measurements under high
pressure were performed on an iron-based superconductor LaFePO. A steep
increase in superconducting transition temperature (Tc) of LaFePO with dTc/dP >
4 K/GPa to a maximum of 8.8 K for P = 0.8 GPa was observed. These results are
similar to isocrystalline LaFeAsO1-xFx system reported previously. X-ray
diffraction measurements were also performed under high pressure up to 10 GPa,
where linear compressibility ka and kc are presented.
