부산대학교 도서관

High precision calorimetry using superconducting transition edge sensorsrequires the use of superconducting films with a suitable $T_c$, depending onthe application. To advance high-precision macrocalorimetry, we requirelow-$T_c$ films that are easy to fabricate. A simple and effective way tosuppress $T_c$ of superconducting Iridium through the proximity effect isdemonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Aufilms fabricated by applying heat to the substrate during Ir deposition havebeen used in the past for superconducting sensors, we present results of $T_c$suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayersand Ir/Pt bilayers in the range of $\sim$20-100~mK. Measurements of therelative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricatedshow factor of $\sim$10 higher values in the Ir/Pt case. These new films couldplay a key role in the development of scalable superconducting transition edgesensors that require low-$T_c$ films to minimize heat capacity and maximizeenergy resolution, while keeping high-yield fabrication methods.