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The upper critical field Hc2 and the field‐dependent critical current density Jc(H) have been determined for high‐Tc Nb3Ge prepared by the chemical vapor deposition (CVD) process. Measurements were performed on short samples taken from long lengths (∼10 m) of Nb3Ge deposited under various conditions onto metallic substrates. Using the theory of Hohenberg and Werthamer for dirty type‐II superconductors, values of Hc2(0) were extrapolated from resistive measurements of Hc2 near Tc. Values of Hc2(0) ranged from 32.2 to 33.1 T, the highest upper critical field reported for bulk Nb3Ge. From measurements of Jc(H), pinning force densities Fp were calculated and compared to the Kramer model of flux pinning which predicts certain scaling laws for Fp. We have tested for these scaling laws and have found qualitative agreement with the model of Kramer. This represents the first demonstration of such scaling in bulk high‐Tc Nb3Ge. In addition, values of the flux line lattice shearing parameter Ks have been extracted f...

Metastable Fe alloys containing up to 25 at.% Ga, obtained by rapidly quenching from the liquid state, have been studied using the Mossbauer effect. A least‐squares analysis of the data has allowed identification of individual configurations of atoms surrounding each Fe atom and the comparison of these configurations with various ordered and disordered states. Partial ordering of the BiF3 type has been definitely observed at 25 at.% Ga, and the results suggest that is may extend to compositions as low as 20 at.% Ga.

Measurements are presented of the temperature variation of the critical current density Jc for superconducting Nb3Ge in the field range 0–65 kG. Samples prepared either by sputtering or chemical vapor deposition (CVD) show a behavior similar to that exhibited by Nb3Sn. The data can be approximated by the relationship Jc∼[Hc2(t)]n. The n values range from 1 for self‐field Jc to 5 at a field intensity of 50 kG.