Twin boundaries in 10M martensite of Ni-Mn-Ga alloy

0471625 - FZÚ 2017 CZ eng D - Dizertace
Kopecký, Vít
Twin boundaries in 10M martensite of Ni-Mn-Ga alloy.
České vysoké učení technické v Praze, Fakulta jaderná a fyzikálně inženýrská. Obhájeno: Praha. - Praha: ČVUT, 2016. 57 s.
Institucionální podpora: RVO:68378271
Klíčová slova: Ni-Mn-Ga * twin boundary * magnetic domains * twin boundary mobility * magnetic shape memory effect
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus

This work is an experimental study of modulated 10M martensite of Ni-Mn-Ga alloy. We aimed on study of single a/c twin boundary mobility. Due to two types of highly mobile a/c twin boundary, Type I and Type II, we focused on determination of differences in their mobility. Several experimental techniques were used, mainly magnetization measurement (vibrating sample magnetometer), optical microscopy (Nomarski contrast and polarization contrast) and custom-made small-forces deformation machine. Even though our
investigation was purely macroscopic, it brought valuable informations. Our approach to reasoning the origin of the extremely low twinning stress of mobile twin boundaries in Ni-Mn-Ga can be hopefully inspirational for formulation of a proper theory describing the phenomena.
Trvalý link: http://hdl.handle.net/11104/0268980