Ho-hum to high performance: Researchers ‘stretch’ a lackluster material into a possible electronics revolution

ITHACA, N.Y. — It’s the Clark Kent of oxide compounds, europium titanate and – on its own – it is pretty boring. But slice it nanometers thin and chemically stretch it, europium titanate takes on super hero-like properties that could revolutionize electronics, according to new Cornell research. (Nature, Aug. 19, 2010.)

Publishing in the journal Nature Aug. 19, researchers report that thin films of europium titanate become both ferroelectric (electrically polarized) and ferromagnetic (exhibiting a permanent magnetic field) when stretched across a substrate of dysprosium scandate, another type of oxide. Up until now, the best simultaneously ferroelectric, ferromagnetic material to date pales in comparison by a factor of 1,000.

Simultaneous ferroelectricity and ferromagnetism is rare in nature and coveted by electronics visionaries. A material with this magical combination could form the basis for low-power, highly sensitive magnetic memory, magnetic sensors or highly tunable microwave devices. Continue reading →

The Center for Emergent Materials is teaming up with COSI to present “Shaping the Future,” a materials science-themed day of hands-on activities for visitors to COSI. From 10am-3:30pm, activity carts will be set up in the museum’s atrium. For more information, directions, hours, etc please see the COSI website at www.cosi.org.

Annual Presenting Sponsor: Connect a Million Minds
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Please join us for a CEM Special Seminar

Wednesday June 2nd from 4:00-5:00 pm
Room 4138 of the Physics Research Building
Light refreshments will be served.

Dilute Nitrides and Flexible Electronics Research at NCA&TSU

Shanthi Iyer
Department of Electrical and Computer Engineering,
North Carolina A&T State University, Greensboro, NC

Dilute nitrides are an exciting new class of semiconductors based on combining group III-N with III-V materials. The large differences in the electro-negativities between N and the cations in these alloys cause a vast band gap bowing as a function of composition. Thus, these alloys with a small amount of N permit rear possibility of simultaneous reduction in the band gap and the lattice parameter, with potential long wavelength emission in otherwise wide band gap III-V materials. A brief review of our work on different mixed As-Sb-dilute N alloys, namely GaAsSbN QWs, GaSbN QWs, InGaAsSbN QWs, and thick GaAsSbN/GaAs lattice matched epilayers, grown by molecular beam epitaxy (MBE) for various optoelectronic applications will be presented.
Flexible electronics is another area of ongoing research in our group. Results on the transparent low work function inorganic material, namely GaAlAsN grown by MBE, F-doped ZnO TCO films on PEN substrates by RF sputtering, and ZnO based alloy thin film transistors will be presented. Continue reading →