We are developing X-ray microcalorimeters using superconducting transition-
edge sensors (TESs), which can be operated at relatively high base temperat
ures of a He-3 cryostat. For this purpose, we have selected Ti films to be
used as TESs. The Ti films were deposited on different substrates by RF-spu
ttering. It was found that the superconducting properties of the Ti films d
epended on Ar pressure, film thickness, and substrate surface roughness. (C
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