In the iron arsenide compound BaFe2As2, superconductivity can be induced
either by a variation of its chemical composition, e.g., by replacing Fe with
Co, or by a reduction of the unit-cell volume through the application of
hydrostatic pressure p. In contrast to chemical substitutions, pressure is
expected to introduce no additional disorder into the lattice. We compare the
two routes to superconductivity by measuring the p dependence of the
superconducting transition temperature Tc of Ba(Fe(1-x)Cox)2As2 single crystals
with different Co content x. We find that Tc(p) of underdoped and overdoped
samples increases and decreases, respectively, tracking quantitatively the
Tc(x) dependence. To clarify to which extent the superconductivity relies on
distinct structural features we analyze the crystal structure as a function of
x and compare the results with that of BaFe2As2 under pressure.Comment: 14 pages, 4 figures, to be published in JPSJ Vol. 79 No. 12. The
copyright is held by The Physical Society of Japa