TOWARDS ANALYSIS OF THE ELECTRON DENSITY OF STATES OF Nb3Sn AS A FUNCTION OF STRAIN

An experiment is conducted to determine the effect of uni-axial strain on the superconducting and microscopic properties of bulk Nb3Sn. Methods of calculating the electron DOS are explored in order to investigate whether the strain sensitivity of the superconducting properties is correlated to changes in the electron density of states. Two different methods are developed to calculate the Sommerfeld constant from resistivity data, which is then related to the electron DOS. The methods are applied to the data and γ * = (1.2±0.2) × 10 3 JK -2 m -3 and (1.2±0.1) × 10 3 JK -2 m -3 are found, very close and consistent with literature results. It is observed that applying 0.6 % compressive uni-axial strain at 19 K reduces the normal state resistivity by 13 %. Furthermore, the change in resistivity between strain states is temperature dependent, with a maximum change close to 40 K. As the measured behavior is not consistent with expectations, the electron DOS as function of strain cannot be calculated at this time. Studying the effect of strain on the superconducting and normal state properties of Nb3Sn is important for understanding the origin of strain sensitivity in Nb3Sn conductors.