Superconducting Hc-Jc and Tc Measurements in the Nb–Ti–N, Nb–Hf–N, and Nb–V–N Ternary Systems

Abstract

Superconducting critical fields, current densities and temperatures have been measured as a function of composition in the Nb–Ti–N, Nb–Hf–N and Nb–V–N ternary systems. In the Nb–Ti–N system the upper critical fields increase sharply and monotonically with increasing NbN concentration to over 130 kOe at about 90 mole % NbN. In the Nb–Hf–N system the highest upper critical-field value observed was 130 kOe for the composition Nb0.92Hf0.08N. In the Nb–Hf–N system the Tc increases monotonically with NbN concentration, in the Nb–Ti–N system a maximum in Tc exists at about 65 mole % NbN and in the Nb–V–N system a broad minimum exists between 30 and 50 mole % VN.

Least-squares refinement of biaxial stress components and unit-cell parameter in a 〈111〉 textured cubic TiN polycrystalline thin film by X-ray diffraction

“…The value of the unit-cell parameter a 0 of titanium nitride is known to be affected by lattice defects and nonstoichiometry due to diffusion of Ti and/or N atoms into or out of the titanium nitride lattice. Therefore, there is no surprise that the optimized unit-cell parameter, a 0 =4.2332 Å, for the TiN film used in this study is different from that of a 0 =4.2433 Å reported by Yen et al (1967).…”

“…However, values of 〈ε X (β, φ, ψ)〉 need to be determined first from the observed Bragg angles, 2θ (obs.). An initial unit-cell parameter a 0 for the unstressed TiN film was needed to start the linear LSR analysis and the value of a 0 =2433 Å from Yen et al (1967) was used. The values of the strains determined from the 2θ (obs.…”

Uakitite, VN, a New Mononitride Mineral from Uakit Iron Meteorite (IIAB)

“…In general, the crystal structure and properties of well-known synthetic VN (or δ-VN) have been studied in detail [29,30,40,42,44,51,62,[64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82]. It is a cubic NaCl-type structure (Fm-3m, a ≈ 4.135 Å, Z = 4).…”

Re-evaluation of formulae for X-ray stress analysis in polycrystalline specimens with fibre texture: experimental confirmation

“…The X-ray absorption coefficient for TiN is evaluated to be TiN = 9.10 Â 10 2 cm À1 for Cu K 1 radiation ( = 1.5404 Å ), where the mass density TiN = 5.55 g cm À3 used for obtaining the X-ray absorption coefficient was estimated from the lattice constant of TiN given by Yen et al (1967) (4.24 Å ). The X-ray penetration depth for this radiation is about 2.2 mm for the measurement of a high-angle reflection, which is about twice the thickness of the TiN film specimen.…”