  We report the adiabatic temperature change in ErAl2 magnetocaloric wires
fabricated by a powder-in-tube (PIT) process. The adiabatic temperature change
of the PIT wires is found to be determined by not only the volume fraction of
ErAl2 core but also the magnitude relationship between the specific heat of the
ErAl2 core and the metal sheath. We propose a quantitative analysis method for
calculating the temperature and core volume fraction dependence of adiabatic
temperature change in the PIT wire, whose formula is applicable to also various
magnetocaloric composites, useful to estimate the magnetocaloric response prior
to fabrication.
