[en] We have studied the effects of transition-metal (TM) and metalloid (M) substitution in amorphous molybdenum-based TM-M alloys. Absolute-specific-heat measurements of thin-film (approx. 1 μm thick) samples of Mo-Ge, Mo-Si, and Mo-Ti-Si alloys prepared by magnetron sputtering were made using the relaxation-time-constant method. A comparison of the superconducting transition width made both thermally and electrically indicates that the sample homogeneity is better than 0.1% for length scales greater than the coherence length. Both the electronic density of states and T/sub c/ with increasing metalloid concentration and [Ti]/[Mo] ratio, in agreement with a rigid-band model. We compare our results to current theories relating the electron-phonon coupling constant lambda/sub e/-ph to the electronic density of states

[en] We have made absolute specific-heat measurements through the metal-insulator transition in thin-film Mo/sub x/Ge/sub 1-//sub x/. We report results for γ and β and infer the thermodynamic electronic density of states. The density of states shows no critical behavior at the metal-insulator transition. There is also evidence of anomalous excess specific heat below the metal-insulator transition. We compare our results to current theories on localization and electron interactions

[en] Improved film synthesis has allowed us to prepare Nb₃Ge/SiO/sub x//Pb tunnel junctions on samples with high T/sub c/ (up to 21.2 K) and large energy gap (Δ3Ge up to 3.85 meV). These junctions have satisfactory features for taking derivative measurements. The data were reduced by the modified McMillan-Rowell proximity gap inversion analysis developed by Arnold and Wolf to generate α²F(ω) and related microscopic parameters. The trend previously seen of a movement of the lowest phonon branch to lower energies as the T/sub c/ and gap increase is continued, resulting in the lowest-energy phonon mode being well defined and enhanced in strength. Theoretical functional derivatives for T/sub c/ (by Bergmann and Rainer) and the energy gap (by Mitrovic et al.) qualitatively explain the rise in T/sub c/, energy gap, and 2Δ/k/sub B/T/sub c/. Heat-capacity measurements have been performed on various samples to give bulk Nb₃Ge properties, including one sample which was analyzed by tunneling α²F(ω) and heat capacity. γ = 34 +- 1.5 mJ/mole K² and the bare density of states, N(0) = 1.5 +- 0.1 states/eV atom, suggests that a high density of states is inadequate to explain the high T/sub c/ in Nb₃Ge. Values for 2Δ/k/sub B/T/sub c/ = 4.2 +- 0.1 and ΔC/γT/sub c/approx.1.9 indicate a strong-coupled superconductor, in agreement with tunneling results on this sample

[en] Experiments showed that a detectable sonic signal is produced by energetic proton beams traversing fluids. The novel results are in agreement with predictions of a thermal expansion model of the generation of the acoustic wave. They are inconsistent with any significant contributions from several other possible sonic generation mechanisms, e.g., microbubble implosion and molecular dissociation. Frequency and amplitude distributions, radiation patterns, and thermal, pressure, and acoustic medium dependences were explored. 5 figures

[en] We present the first specific-heat measurements of artificially layered superconducting structures. Using small sample calorimetry, we have measured the specific heat of Nb-Zr multilayers. Samples with Λ, the bilayer period, varying from 32.8 to 429 A (with total sample thickness of 1.5 μm were studied in a temperature range 1.5--20 K. We obtained the effective theta/sub D/ and γ for the samples as well as ΔC/γT/sub c/. .AE

[en] We have studied the electrical resistivity and heat capacity for multilayers of niobium and zirconium prepared by magnetron sputtering for values of the bilayer period Λ varying from 4 to 950 A. We find a transition in the thermal part of the resistivity that correlates with the coherent-to-incoherent transition seen in earlier work. The heat capacity data for the normal state show anomalous behavior for both the electronic coefficient γ and the Debye temperature. We also study the variation in T_c and the jump in the specific heat

[en] This work establishes that a detectable sonic signal is produced by protons while traversing through or stopping in a fluid medium. Experiments exploring the global characteristics of both the acoustic generation mechanism and the radiation pattern were performed at three different accelerators. The results are consistent with a simple thermal model for the transformation of the energy of moving charged-particles into acoustic energy. This phenomenon could be exploited in several applications: (1) as a charged particle monitor in accelerator beams, (2) as a heavy-ion detector sensitive to nuclear charge, e.g., in measuring cosmic ray isotopes (3) as an inexpensive shower detector in massive neutrino detectors at the next generation of high-energy accelerators, e.g, the Fermilab energy doubler and (4) as the shower calorimeter (and perhaps the muon detector) in massive deep underwater detectors of cosmic neutrino and muon interactions

[en] Recent experiments at Brookhaven National Laboratory and Harvard University demonstrate that a detectable sonic signal is produced by energetic proton beams while traversing a fluid medium. The observed acoustic wave agrees with the predictions of a thermal expansion model. Results are inconsistent with any significant contribution from either microbubble implosion or molecular dissociation, two other suggested means of sonic production. Frequency and amplitude distributions, radiation patterns, temperature, pressure, and medium dependences are explored. This phenomenon may have immediate applications in beam monitoring and in detecting energetic heavy ions. Signal thresholds may be low enough to permit detection of particle showers induced by single particles at the next generation of high energy accelerators or from high energy cosmic rays. The inexpensive transducers and long sonic transmission lengths obtainable in liquids suggest that high energy particle detectors may be feasible with masses many orders of magnitude greater than those currently in use. (Auth.)