Clarifying the crystallization path, from the thermodynamic point of view, is of importance for the structure and properties of metallic glasses (MGs). The influence of oxygen on the crystallization pathway of Ni65Zr35 MG was investigated by in-situ heating transmission electron microscopy (TEM). As temperature increases, crystalline Ni7Zr2 and t-ZrO2 phases are formed first rather than the Ni10Zr7 and Ni21Zr8 phases, which are the main crystallization products following the phase diagram. Oxygen changes the crystallization pathway by varying the Ni/Zr ratio, indicating that the effects of oxygen on the crystallization in nanometer-sized MG cannot be neglected even in high vacuum TEMs.
