Thermal conductivity and electrical resistivity of NbTi alloys at low temperatures

Penetration depth and critical fields in superconducting NbTi thin films grown by co-sputtering at room temperature

“…The film displays a residual resistivity ratio (RRR) of 1.3 and a room-temperature resistivity (ρ RT ) of 5 μΩ•cm. Figure 3(a) displays a summary of the normalized resistance as a function of temperature without and with applied fields up to 9 T. The sample is characterized by a sharp superconducting transition with T c = 9.65 K (defined at 50% of the change in resistance), as expected for high-quality alloys [20,26]. Indeed, for zero field, considering the onset of T c (defined as 90% of the change in resistance) and the offset of T c (defined as 10% of the change in resistance), the difference is smaller than 0.1 K. As a magnetic field is applied, the transition shifts to lower temperatures while conserving its sharpness.…”

“…Next, we analyze the superconducting critical temperature and the upper critical field by performing electrical transport measurements and applying a magnetic field up to 9 T along the c-axis. The maximum critical field for NbTi takes place close to the 1:1 atomic ratio [25,26]. The film displays a residual resistivity ratio (RRR) of 1.3 and a room-temperature resistivity (ρ RT ) of 5 μΩ•cm.…”

Electrical Resistivity of Nb–Ti Superconductors

“…The superconducting transition temperature Tc was measured and is shown in Fig. 3 as a function of Ti-concentration, together with data given by several investigators(4)- (7). The value of Tc is determined as the mean value of the Fig.…”

Structural and superconducting properties of Nb-Ti alloy thin films

“…This increase in Pn more than compensates for the slight decrease in 7, the electronic specific heat coefficient and To, resulting in the enhancement of the upper critical field Hez for the Ti rich alloys (Larbalestier 1981). The incipient instability of the/~-phase in the Ti rich composition region plays an important role in the anomalous increase in the resistivity and the enhancement of rio2 (Prekul et al 1974;Collings 1980;Bychkov et al 1981;Hochstuhal and Obst 1982;Hariharan et al 1984Hariharan et al , 1986. This instability of the t-phase is relieved by one of a variety of structural transformations (Hariharan et al 1986).…”