We report on the fabrication and investigation of few-nanometers-thick superconducting molybdenum-rhenium (Mo-Re) films intended for use in nanowire single-photon superconducting detectors (SSPDs). Mo-Re films were deposited on sapphire substrates by DC magnetron sputtering of an Mo(60)-Re(40) alloy target in an atmosphere of argon. The films 2-10 nm thick had critical temperatures (T c ) from 5.6 to 9.7 K. HRTEM (high-resolution transmission electron microscopy) analysis showed that the films had a homogeneous structure. XPS (x-ray photoelectron spectroscopy) analysis showed the Mo to Re atom ratio to be 0.575/0.425, oxygen concentration to be 10%, and concentration of other elements to be 1%.

The "metallic" temperature variation of the electrical resistivity of chemical nano goldsilver coatings with a silver content of 6.6% at. up to 13.1% at. determined in the temperature range 4.2-300 K. Features of low-temperature measurements of the resistance of nano-coatings were found and explained. The possibility of the appearance of superconductivity in them is discussed. IntroductionIn July 2018, a message appeared from Indian scientists about the development and properties of a new superconducting compound in the form of a chemical coating of nanoparticles (NPs) of gold with silver [1]. The temperature dependences of the resistance of manufactured coatings, on which the linear change of resistance typical for metals is replaced by a sharp drop to zero in the temperature range of 236 K (-37 °C) characteristic of the superconducting transition, are presented in this message. Measurement of the magnetic permeability of the coating samples showed the presence of a diamagnetic response below the transition temperature, which indicates the presence of the Meissner effect. In addition, an external magnetic field of 0.1 to 3 T biased the beginning of the transition to lower temperatures.The combination of these experimental results is usually sufficient evidence of the existence of superconductivity. It was also reported that one of the samples had a transition temperature of 320 K (+47 °C), which meant that room temperature superconductivity (PCB) was achieved for the first time in the history of superconductivity with normal external atmospheric pressure. Attempts to test the possibility of the existence of such a compound [2,3] after the specified message were made. In [2], nanoscale films consisting of alternating layers of gold and silver were made and studied. It should be noted that the vacuum thermal method of sputtering gold and silver, applied in [2], is very far from the chemical synthesis of these components in [1]. As a result, superconductivity has not been found out. The technique for

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