Interfacial Exotic Physical Phenomena in Artificially Stacked Hetero-structures
* ID: 819 8066 7842 / PW: 190439
- Title : Interfacial Exotic Physical Phenomena in Artificially Stacked Hetero-structures
- Abstract : “The interface is the device” was famously quoted by Herbert Kroemer in his Nobel lecture in 2000. Keeping this in mind, I will briefly discuss about the exotic interfacial physical phenomena arise at the interfaces of all perovskite oxides, oxide-semiconductor, and metal-organic heterostructures. The breaking of orthorhombic to tetragonal crystal symmetry is realized by increasing the layer thickness in the superlattices consisting of 17 unit cell thick and n (1,2,..,16) unit cell of . By stabilizing tetragonal symmetry, we have achieved a very strong in-plane antiferromagnetic (AFM) ordering, negative perpendicular magnetic anisotropy, two-step magnetic switching, robust dual exchange bias in the temperature and/or field dependent magnetization studies along with the tunneling like transport with anomalous anisotropic behavior, observed in field dependent magnetoresistance. Whereas, the orthorhombic crystal symmetry is associated with the weaker interfacial AFM ordering and stronger spin-orbit coupling due to the reduction in Ru 4d orbital occupancy and larger orbital overlapping, respectively. These features are analyzed by using Meiklejohn-Bean model, Stoner-Wohlfarth model, and density functional theory. Further, by adopting a unique pulsed plasma deposition method, we have also been able to grow the only (00l) oriented complex oxide thin films on bare Si substrates for industrial applications. Interestingly, these thin films exhibit positive magnetoresistance, which can be attributed to the lack of half-metallicity. On the other hand, the organic molecules have been proven to be an important tool to significantly manipulate the interfacial magnetic anisotropy of the 3d-transition metals. The ultra-fast control of these exotic and tunable interfacial physical phenomena is the need of the hour for the development spintronics based devices for betterment of human life and environment.
Host : Prof. Tae Won Noh