On the Vibrational Spectrum and the Vibrational Specific Heat of a Binary Superlattice Alloy

The change in the vibrational modes of a binary superlattice alloy due to the change in its own degree of order has previously been discussed. It was then expected that the vibrational specific heat of the superlattice alloy would change in response to the change in its own degree of order. Using the result obtained formerly, we have applied, in the present paper. Houston\u27s approximate method of finding the frequency distribution function N(ν) to the calculation of the vibrational specific heat of β-brass in the state of any specified degree of order. It is shown that the vibrational specific heat of the disordered alloy is generally larger than that of the ordered one at oridnary temperatures. If two kinds of atoms which are the components of alloy are nearly equal in mass, the vibrational specific heat of the ordered alloy becomes larger than that of the disordered one at low temperatures

The Measurement of the Young\u27s Modulus of Metals and Alloys by an Interferometric Method. III : The Influence of Heat-Treatment on the Young\u27s Moduli of Fe-Al Alloys, and the Young\u27s Moduli of Ni-Al, Al-Cu Alloys and German Silver in the Annealed State

The measurement described in the earlier papers of this series has been extended to the study of the influence of heat-treatment on the Young\u27s moduli of Fe-Al alloys having the composition up to 14.75 per cent aluminium. It becomes clear that the Young\u27s modulus of ordered Fe_3Al (13.8 per cent aluminium) is smaller than that of disordered one. This result is contrary to the cases of Cu_3Au and Ni_3Mn. Moreover, measurement has been done on the static Young\u27s moduli of Ni-Al alloys (up to 5.17 per cent aluminium), several specimens of Al-Cu alloys and german silver. The Young\u27s modulus vs. composition curve of Ni-Al alloys seems to be akin to the curve peculiar to Ni-alloys, such as Ni-Cu and Ni-Mn systems

Superconductivity of Dilute Primary Solid Solutions of In-Mg and In-Pb

By measuring magnetic moments and electrical resistances of pure indium and indium alloys containing 0.28 to 13.7 atomic per cent of magnesium and 0.06 to 0.73 atomic per cent of lead at liquid helium temperatures, the variation of the superconducting critical temperature, T_c, with the concentration of solute metals was studied. T_c decreases initially with the increasing concentration of solute in so far as a small amount of solute metals is concerned. When the amount becomes large, the alloying effect of magnesium differs from that of lead, i.e., in the former case T_c continues to decrease steadily, while in the latter it shows a gradual increase after passing through a minimum. These results qualitatively agree with the theoretical consideration of Anderson and of Nakamura. The threshold magnetic field at 0°K and the coefficient of electronic specific heat in the normal state were estimated from the data obtained

The Measurement of the Young\u27s Modulus of Metals and Alloys by an Interferometric Method. I : The Young\u27s Modulus of Ni-Cu Alloys

A description is given of the bending apparatus making use of an interferometric method, and the device for eliminating perfectly the disturbing mechanical vibrations. The experimental results obtained by this statical method on the Young\u27s modulus of Ni-Cu alloys proved to agree qualitatively with Yamamoto\u27s results which were obtained by the dynamical method

The Measurement of the Young\u27s Modulus of Metals and Alloys by an Interferometric Method. II : The Influence of Heat-Treatment on the Young\u27s Moduli and Densities Ni-Mn Alloys

An investigation has been performed on the change of the Young\u27s modulus and the density of Ni-Mn alloys, having the composition from 1.43 to 23.8% Mn, when they were subjected to various heat-treatments. The results obtained are as follows. (1) The Young\u27s modulus of the alloys which were worked or quenched decreases monotonously with the increase of manganese content, but after the samples were annealed thoroughly for many hours, Young\u27s modulus vs. composition curve does not show such a monotonous behaviour as in the former cases. (2) The Young\u27s modulus of Ni_3Mn in the ordered state is larger by more than 10 per cent than that in the disordered state. (3) The influence of the heat-treatment on the density could not be found beyond the limits of experimental error