Two Dimensional Magnetic Oxides
Comprehensive Exam
1:00 pm –
2:00 pm
Jorgensen Hall
Contact:
Physics Department, (402) 472-2770, paoffice2@unl.edu
Ahsan Ullah will present his comprehensive exam topic, “Two Dimensional Magnetic Oxides” via Zoom.
ABSTRACT: The physical and chemical properties of materials confined in two dimensions (2D) have been heavily studied after the discovery of graphene. For example, many van der Waals and non-van der Waals 2D materials have been exfoliated for the search of ferromagnetic order in 2D and its application in storage media and spintronics. Transition metal magnetic oxides have good stability in a normal environment and can be used for the study of 2D magnetic oxides. Here we discuss the 2D layers exfoliated from magnetic oxides show the enhanced and stable magnetic order as compared to their bulk counterparts, which are normally antiferromagnetic due to strong superexchange interactions. We focus on the effect of lack of symmetry due to 2D confinement on crystal field interactions, spin-orbit interaction, and magnetic anisotropy energy. We propose that the alloying of magnetic oxides and hence 2D exfoliated magnetic oxides will not only change the superexchange interaction but will also change magnetic anisotropies and spin-orbit interactions. These changes in interactions depend on the type of impurities whether it’s magnetic or nonmagnetic. Some possible experiments and computational studies based on doped magnetic oxides have been suggested for the search for new stable 2D magnets.
ABSTRACT: The physical and chemical properties of materials confined in two dimensions (2D) have been heavily studied after the discovery of graphene. For example, many van der Waals and non-van der Waals 2D materials have been exfoliated for the search of ferromagnetic order in 2D and its application in storage media and spintronics. Transition metal magnetic oxides have good stability in a normal environment and can be used for the study of 2D magnetic oxides. Here we discuss the 2D layers exfoliated from magnetic oxides show the enhanced and stable magnetic order as compared to their bulk counterparts, which are normally antiferromagnetic due to strong superexchange interactions. We focus on the effect of lack of symmetry due to 2D confinement on crystal field interactions, spin-orbit interaction, and magnetic anisotropy energy. We propose that the alloying of magnetic oxides and hence 2D exfoliated magnetic oxides will not only change the superexchange interaction but will also change magnetic anisotropies and spin-orbit interactions. These changes in interactions depend on the type of impurities whether it’s magnetic or nonmagnetic. Some possible experiments and computational studies based on doped magnetic oxides have been suggested for the search for new stable 2D magnets.