Resistivity Of Amorphous Metals Research Articles

Processing and characterization of Ni63Cr12Fe4Si8B13 amorphous alloy for the manufacturing of electrical resistances

Amorphous alloys exhibit random atomic arrangements in solid state form, and the phenomena of segregation and grains boundaries are absent. These alloys are obtained by rapid quenching techniques of the melt, with cooling rates of 105 … 106 ℃/s. As a result of the requirement of an extremely high cooling rate, their delivery forms are usually limited to thin films, thin ribbons and, powders. The resistivity of amorphous metals does not depend on temperature as in the case of crystalline ones, exemplified in a situation in which a Pd76Si20Cr4 alloy was heated to a temperature of 4000 K and it was observed that the resistivity in the case of the amorphous alloy increased 3 times higher than in the case of the crystalline alloy. The chemical composition of the processed alloy, in which Si and B are added to stabilize the amorphous phase, leads to an electrical resistivity of 1.72 × 10−6 Ωm and an electrical resistance of 2.9 Ω, which is 3 times higher than that of the Ni-based crystalline alloy, from which the electrical resistances are manufactured.

Phonon characterisation and the theory of the temperature dependence of the electrical resistivity of amorphous metals

The dependence of the dynamic and static structure factor and the temperature-dependent part of the electrical resistivity on the spatial correlations of the lattice vibrations is investigated. For this purpose an amplitude correlation function for the lattice vibrations is introduced and expressed in terms of a correlation length. The authors' numerical model calculations show that a negative temperature coefficient of the electrical resistivity is favoured by a short correlation length.

Theory of the Electrical Resistivity of Amorphous Metals

A theory of the electrical resistivity of amorphous metals is presented. Anharmonicity of the lattice vibration brings about the movement of the equilibrium positions of atoms as the amplitude of the lattice vibration becomes large. As a result the lattice becomes less distorted. It is predicted that the resistivity decreases with increasing temperature in proportion to T 4 at low temperatures and to T at high temperatures.