Rapid appearance of domains upon phase change in KNbO3 - a TEM in-situ heating study

TL;DR

This study used in-situ TEM heating to observe rapid domain pattern changes and interactions with dislocations in potassium niobate, revealing dynamic phase transitions and domain behavior.

Contribution

It provides real-time insights into domain dynamics and phase change mechanisms in KNbO3 during heating, highlighting the interaction between domain walls and dislocations.

Findings

Rapid appearance of new domain patterns during phase change

Domain walls become pinned by dislocations temporarily

Observation of mobile and interacting domain walls and dislocations

Abstract

TEM specimens from potassium niobate single crystals were observed while being heated in a TEM. DWs and dislocations were observed; the DWs were mobile. In certain cases the DWs became pinned by the dislocations, at least for a short time, most likely due to interaction of strain fields. Both phase changes were observed with accompanying rapid appearance of new domain patterns.