  Single crystals of the unconventional superconductor UTe$_2$ have been grown
in various conditions which result in different superconducting transition
temperature as well as normal state properties. Stoichiometry of the samples
has been characterized by the single-crystal X-ray crystallography and electron
microprobe analyses. Superconducting samples are nearly stoichiometric within
an experimental error of about 1 \%, while non-superconducting sample
significantly deviates from the ideal composition. The superconducting UTe$_2$
showed that the large density of states was partially gapped in the normal
state, while the non-superconducting sample is characterized by the relatively
large electronic specific heat as reported previously.
