Elasticity, thermal expansion and compressive behavior of Mg65Cu25Tb10 bulk metallic glass

The existence of special covalently bonded short-range ordering structures in a Mg65Cu25Tb10 bulk metallic glass (BMG) is confirmed by thermal expansion and compression behavior. Under ambient conditions the linear thermal expansion coefficient obtained is almost constant in the glassy state with a value of 4.0 × 10−5 K−1. By fitting the static equation of state at room temperature under ambient conditions we find the value for bulk modulus B of 48.7 GPa, which is in excellent agreement with the experimental study by pulse-echo techniques of 44.7 GPa. Unlike many bulk metallic glasses, such as Zr- and Pd-based, which bulk modulus is much larger than 100 GPa, the value B of Mg65Cu25Tb10 BMG falls into the range of SiO2 and fluorozirconate glass ZBLAN. Moreover, the elastic constant of the Mg65Cu25Tb10 BMG is almost the same as those of ZBLAN. No evidence for the high-pressure phase transitions of the Mg65Cu25Tb10 BMG has been found up to 31.19 GPa at room temperature.