  A high-entropy-alloy-type (HEA-type) superconductor is new category of highly
disordered superconductors. Therefore, finding brand-new superconducting
characteristics in the HEA-type superconductors would open new avenue to
investigate the relationship between structural disorder and superconductivity.
Here, we report on the remarkable broadening of specific heat jump near a
superconducting transition tempreature (Tc) in transition-metal zirconides
(TrZr2) with different mixing entropy ({\Delta}Smix) at the Tr site. With
increasing {\Delta}Smix, the superconducting transition seen in specific heat
became broader, whereas those seen in magnetization were commonly sharp.
Therefore the broadening of specific heat jump would be related to the
microscopic inhomogeneity of the formation of Cooper pairs behind the emergence
of bulk superconductivity states.
