The electrical resistance and thermal conductivity of Ti 15V–3Cr–3Sn–3Al at cryogenic temperatures

Abstract

Ti 15V–3Cr–3Sn–3Al, sometimes referred to as Ti 15-3-3-3 or “Magic Titanium”, is a candidate material for components requiring high mechanical strength and low thermal conductivity at cryogenic temperatures. The electrical resistance of Ti 15-3-3-3 was measured between 230 mK and room temperature, and the thermal conductivity between 230 mK and 7.7 K. A superconducting transition was observed at T C = 3.89 ± 0.01 K. Below the superconducting transition temperature, the thermal conductivity was fitted to a function of the form λ ( T < T C ) = α · T · e - β · T C / T , where α = 0.043 ± 0.002 W/(m K 2) and β = 0.27 ± 0.01. Above T C , the thermal conductivity of Ti 15-3-3-3 was fitted to a function of the form λ( T > T C ) = γ · T δ , where γ = α · T C 1 - δ · e - β and δ = 0.4 ± 0.05. The thermal conductivity of Ti 15-3-3-3 is compared with other materials commonly used for the construction of thermally isolating support structures. Ti 15-3-3-3 is shown to exhibit one of the lowest ratios of thermal conductivity to mechanical strength and is thus particularly well suited for such applications.