Superconductivity, magnetic susceptibility, and electronic properties of amorphous ${\left({\mathrm{Mo}}_{1-x}{\mathrm{Ru}}_x\right)}_{80}{\mathrm{P}}_{20}$ alloys obtained by liquid quenching

Results of x-ray diffraction, transmission-electron diffraction, and crystallization studies on amorphous ${\left({\mathrm{Mo}}_{1-x}{\mathrm{Ru}}_x\right)}_{80}{\mathrm{P}}_{20}$ alloys obtained by liquid quenching are presented and discussed. The alloys are all found to be superconducting with transition temperatures ranging from ∼ 3 to ∼ 9°K. The variation of $T_c$ with alloy composition is compared to that obtained by Collver and Hammond for vapor-quenched transition-metal films. Results of magnetic-susceptibility measurements are used to estimate the variation of the electronic density of states at the Fermi level $N\left(0\right)\mathrm{}$ from the Pauli paramagnetic contribution. The relationship between the variation of $T_c$ and $N\left(0\right)\mathrm{}$ is discussed in terms of the microscope theory of superconductivity. Finally, results of measurements of the upper critical field $H_{c2\mathrm{}}$, and the normal-state electronic transport properties are presented and compared with recent theoretical models for amorphous superconductors.