Spontaneous strain glass to martensite transition in a Ti 50 Ni 44.5 Fe 5.5 </…
2011; American Physical Society; Volume: 84; Issue: 21 Linguagem: Inglês
10.1103/physrevb.84.214201
ISSN1550-235X
AutoresJian Zhang, Yu Wang, Xiangdong Ding, Zhen Zhang, Yumei Zhou, Xiaobing Ren, Dong Wang, Yuanchao Ji, Minghui Song, Kazuhiro Otsuka, Jun Sun,
Tópico(s)Shape Memory Alloy Transformations
ResumoGlass transition has often been considered as a purely kinetics-controlled freezing process, thus it is not expected that a frozen glass state can spontaneously transform into a long-range-ordered (LRO) phase. Here we show evidence for a spontaneous transition from a frozen strain glass (STG) to a LRO martensite in a Ti${}_{50}$Ni${}_{44.5}$Fe${}_{5.5}$ alloy: the alloy freezes into a STG at 179 K, but the frozen STG does not keep frozen and it transforms spontaneously into a LRO martensite ($R$ phase) at 154 K. The transition from a frozen STG (with local $R$-like order) into a LRO $R$ phase is explained by considering the existence of a thermodynamic driving force towards LRO. The present result indicates that thermodynamics may also play a role in glass, in addition to the kinetics.
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