| Abstract: | Single crystals of ternary borides ErRh3B (cubic,Pm3m), ErRh3B2 (monoclinic, C2/m) and ErRh4B4 (tetragonal, P42/nmc) have been grown from copper solution by slow cooling method. The electrical resistivity, oxidation resistivity and Vickers microhardness were studied. The electrical resistivities at room temperature of the (100) face of ErRh3B, (001) face of ErRh3B2 and (100) face of ErRh4B4 are 25.6 μΩ·cm, 50.0 μΩ·cm and 106.8 μΩ·cm, respectively. According to thermogravimetric and differential thermal analyses, the oxidation of ErRh3B, ErRh3B2 and ErRh4B4 start at 1030°C, 373°C and 690°C, respectively. The weight gain of the same compounds after heating in air up to 1200°C is 0.7%, 15.44% and 5.4%, respectively. The values of the Vickers microhardness for the (100) face of ErRh3B, the (100) face of ErRh3B2 and the (110) face of ErRh4B4 are 4.8–5.0 GPa, 10.4–10.9 GPa and 10.9–11.3 GPa, respectively. The effect of boron content and crystal structure of each compound on the electrical resistivity, oxidation resistivity and Vickers microhardness are discussed. |
