**Acknowledgements**

*Solid State Physics - Metastable, Spintronics Materials and Mechanics of Deformable...*

and/or hafnium in the range of 45–65 atomic percent, titanium and/or niobium in the range of 4–7.5 atomic percent, and aluminum and/or zinc in the range of 5–15 atomic percent. The balance of the alloy composition comprises copper, iron, cobalt, and nickel. The composition is constrained such that the atomic percent of iron is less than 10%. Furthermore, the ratio of copper to nickel and/or cobalt is in the range of 1:2 to 2:1. Therefore, the alloy glass can be formed at a reduced critical cooling rate without any beryllium addition. The third most-cited patent, US5368659, discloses an invention similar to the above most-cited patent; the alloy forms metallic glass containing beryllium in a narrower range of 2–47 atomic percent, at least one early transition metal in the range of 30–75 atomic percent, and at least one late transition metal in the range of 5–62 atomic percent [42]. Furthermore, the critical cooling rate to achieve the amorphous structure can be reduced to 1–100 K/s or lower. Patent US6325868, the fifth most-cited patent, discloses a nickel-based amorphous alloy composition, particularly a quaternary nickel-based amorphous alloy containing nickel, zirconium, and titanium as the main constituent elements and additive Si or P [44]. The quaternary nickel-zirconium-titanium-phosphorus alloy compositions comprise nickel in the range of 50–62 atomic percent, zirconium and titanium in the range of 33–46 atomic percent, and phosphorus in the range of 3–8 atomic percent, represented by the general formula Nid(Zr1−yTiy)ePf. The nickelbased amorphous alloy compositions have a superior amorphous phase-forming ability, and bulk amorphous alloy having a thickness of 1 mm can be produced by

This study focuses on the analysis of patent data to explore the technological developments of metallic glass materials. The primary findings of this study can be

1.Two obvious increments in patent applications occurred in 1990–2000 and 2000–2015. The former primarily arose from the increased number of patent applications filed in Japan. The latter is mainly attributed to patent applica-

2.Patents related to iron-based alloys are the main category of metallic glass materials for which patents were applied. The reason is that iron-based metallic materials can be used in several applications, especially in the soft magnetic fields.

3.According to the analysis of the present study, metallic glass materials are in the growth stage of the technology life cycle, which implies that increasing amounts of resources will be invested in the metallic glass field for the develop-

4.All of the top ten assignees were from the United States, China, and Japan. The US assignees were from an academic institution, whereas most of their Japanese and Chinese counterparts were from commercial businesses or

5.Patents field by the California Institute of Technology were cited the most frequently, with an average of 16.0 citations, implying their high technological value.

**70**

general casting methods.

summarized as follows:

tions filed in China.

ment of commercial products.

research institutions.

**4. Conclusion**

This work was performed with financial support from the Ministry of Science and Technology of the Republic of China, Taiwan, under Contract MOST 106-2218-E-027-011-MY3.
