Investigation of Interaction between a Dislocation and a Br? Ion in NaCl:Br? Single Crystals

✍ Scribed by Ohgaku, T. ;Teraji, H.

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 128 KB
• Volume: 187
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200110)187:2<407::aid-pssa407>3.0.co;2-q

✦ Synopsis

Subject classification: 62.20.Hh; S9.11 Strain rate cycling tests were carried out under simultaneous Blaha effect measurement on NaCl single crystals doped with Br --. Curves of strain rate sensitivity (SRS) of flow stress versus stress decrement due to superimposition of oscillatory stress were obtained. The curves are stair-like and show two plateau regions at low and higher stress decrement, and a middle region where the SRS decreases with increasing stress decrement, as reported in a previous paper concerning KCl : Br --. The stress t p at the first bending point of the curve, which is considered to be the effective stress due to Br --, decreases with increasing temperature and becomes zero at a critical temperature T c = 270 K. The difference SRS p between the SRS at the first and second plateau regions decreases with temperature in contrast to the case of KCl : Br --. This means that the force-distance profile of the interaction between a dislocation and a Br --ion for NaCl : Br --is different from that for KCl : Br --and is pointed near the top. It is found that the interaction energy between a dislocation and a Br --impurity for NaCl : Br --crystal is 0.37 eV.