Photoemission studies on electron doped cuprate Pr0.85LaCe0.15CuO4: Revisiting the chemical pressure effect Original Research Article

We performed angle resolved photoemission spectroscopy (ARPES) experiments on electron doped cuprates Pr0.85LaCe0.15CuO4 (PLCCO) and Nd1.85Ce0.15CuO4 (NCCO). Critical temperatures (T c) of PLCCO and NCCO are similar but PLCCO has weaker Fermi surface curvature than NCCO. As the ionic radius of Pr and La is larger than that of Nd, this result is inconsistent with the earlier view that chemical pressure determines the Fermi surface curvature. On the other hand, anti-ferromagnetic (AFM) band renormalization effect in PLCCO is larger than that in NCCO, which implies AFM is stronger in PLCCO. This is consistent not only with the view that AFM is correlated with t′/tt′/t but also with recent inelastic neutron scattering results. Therefore, we suggest that the chemical pressure effect is not the only factor that determines the Fermi surface topology.