Physics

Dr. Ashna Bajpai
IISER Pune

Abstract :

The phenomenon of weak ferromagnetism in some otherwise antiferromagnets  is  associated with the famous Dzyaloshinskii Moriya interaction.  Piezomagnetism, also predicted by Dzyaloshinskii in these weak ferromagnets, is a relatively less explored phenomenon.  In this talk, I will discuss remanence measurements conducted on a number of such symmetry allowed weak ferromagnets and  piezomagnets. We consistently observe an ultra-slow magnetization relaxation phenomenon with a counter-intuitive magnetic field dependence. This ultra- slow dynamics manifests itself in the form of a time-stable remanence and appears exclusive to these systems. Though the effect is significantly tunable with nano scaling, it is intrinsic in nature as these features are observed in a bulk single crystal as well. I will show that the magnitude of this time –stable remanence can be significantly enhanced by encapsulation inside carbon nanotubes. I will also show electron transport data conducted on such individual carbon nanotubes. These results illustrate why encapsulation of these functional magnets within carbon nanotubes is promising from both the basic and applied physics point of view.