2018 Taylor Lecture

Materials Processing for Devices

Thursday, April 5, 2018
John Freeman Auditorium, Hub - Robeson Center
Ramamoorthy Ramesh

Electric Field Control of Magnetism

Ramamoorthy Ramesh
Purnendu Chatterjee Chair Professor, Physics / Materials Science, Associate Laboratory Director, Energy Technologies, Lawrence Berkeley National Laboratory
University of California, Berkeley, CA
Abstract: 
Complex perovskite oxides exhibit a rich spectrum of functional responses, including magnetism, ferroelectricity, highly correlated electron behavior, superconductivity, etc. The basic materials physics of such materials provide the ideal playground for interdisciplinary scientific exploration with an eye towards real applications. Over the past decade the oxide community has been exploring the science of such materials as crystals and in thin film form by creating epitaxial heterostructures and nanostructures. Among the large number of materials systems, there exists a small set of materials which exhibit multiple order parameters; these are known as multiferroics, particularly, the coexistence of ferroelectricity and some form of ordered magnetism (typically antiferromagnetism). The scientific community has been able to demonstrate electric field control of both antiferromagnetism and ferromagnetism at room temperature. Current work is focused on ultralow energy (1 attoJoule/operation) electric field manipulation of magnetism as the backbone for the next generation of ultralow power electronics. In this lecture, I will describe our progress to date on this exciting possibility. The lecture will conclude with a summary of where the future research is going.
Shashank Priya

Energy Harvesting Materials and Systems

Shashank Priya
Professor, Materials Science and Engineering
Penn State
Abstract: 
Novel material properties open the possibility of developing new components and systems. These new components and systems require sustainable power source to operate. This synergy between the materials – energy – smart systems has provided the paradigm of “self-powered component and systems” for innovation driving the emergence of efficient and high performance architectures. Some examples illustrating these platforms will be provided in this presentation covering solar, thermal, magnetic field and vibration energy harvesting. The presentation will emphasize recent advances made in synthesis of magnetoelectric laminate composites through combination of aerosol deposition and laser sintering. Interface design through controlled laser annealing has opened the opportunity to achieve high coupling factors responsible for high power density under dual field excitation. The results show that matching the interface mechanical impedance and imposing self-biased response is critical towards achieving high volumetric and power density. Using these laminates, harvesters were fabricated and integrated with wireless sensor nodes. In-depth discussion of the design, modeling and testing procedures will be provided to illustrate the strategy behind achieving high power density and efficiency in vibration, thermal and light harvesters.
Suzanne Mohney

Design of Contacts for Semiconductor Devices

Suzanne Mohney
Professor of Materials Science and Engineering and Electrical Engineering
Penn State
Abstract: 
Coming Soon.
Jun Zhu

Quantum Valley Hall Effect and Valleytronics in Bilayer Graphene

Jun Zhu
Professor of Physics
Penn State
Abstract: 
The advent of two-dimensional materials with hexagonal crystal symmetry offers a new electronic degree of freedom called valley, the manipulation and detection of which could potentially be exploited to form new many-body ground states as well as new paradigms of electronic applications. In this talk, I will describe our effort on creating and understanding valley-momentum locked quantum wires in Bernal stacked bilayer graphene. These quantum wires arise in a topological band structure of bilayer graphene created by state-of-the-art nanolithography and can carry current ballistically. They are signatures of the quantum valley Hall effect. I will also demonstrate the operations of a valley valve and a tunable electron beam splitter, which exploit the new valley degree of freedom. The high quality and versatile controls of the system open the door to many exciting possibilities.