Structure and superconductivity of tin-containing HfTiZrSnM (M = Cu, Fe, Nb, Ni) medium-entropy and high-entropy alloysGačnik, Darja (Avtor) Jelen, Andreja (Avtor) Krnel, Mitja (Avtor) Vrtnik, Stanislav (Avtor) Luzar, Jože (Avtor) Koželj, Primož (Avtor) Van Midden Mavrič, Marion A. (Avtor) Zupanič, Erik (Avtor) Wencka, Magdalena (Avtor) Meden, Anton (Avtor) Hu, Qiang (Avtor) Guo, Sheng (Avtor) Dolinšek, Janez (Avtor) high-entropy alloysstructure and microstructuresuperconductivityIn an attempt to incorporate tin (Sn) into high-entropy alloys composed of refractory metals Hf, Nb, Ti and Zr with the addition of 3d transition metals Cu, Fe, and Ni, we synthesized a series of alloys in the system HfTiZrSnM (M = Cu, Fe, Nb, Ni). The alloys were characterized crystallographically, microstructurally, and compositionally, and their physical properties were determined, with the emphasis on superconductivity. All Sn-containing alloys are multi-phase mixtures of intermetallic compounds (in most cases four). A common feature of the alloys is a microstructure of large crystalline grains of a hexagonal (Hf, Ti, Zr)$_5$Sn$_3$ partially ordered phase embedded in a matrix that also contains many small inclusions. In the HfTiZrSnCu alloy, some Cu is also incorporated into the grains. Based on the electrical resistivity, specific heat, and magnetization measurements, a superconducting (SC) state was observed in the HfTiZr, HfTiZrSn, HfTiZrSnNi, and HfTiZrSnNb alloys. The HfTiZrSnFe alloy shows a partial SC transition, whereas the HfTiZrSnCu alloy is non-superconducting. All SC alloys are type II superconductors and belong to the Anderson class of “dirty” superconductors.20212022-04-06 14:28:45Članek v reviji136015sl