News

September, 2013 - Sara Callori wins Goldhaber prize

Congratulations to Sara on winning the Goldhaber prize! Details here.

April 11, 2013 - Congratulations Dr Sara!

Sara Callori successfully defended her PhD thesis today. She will soon start a postdoc in Sydney, Australia. Congratulations to Sara on an excellent thesis and for setting the current group record for champagne at PhD defense (5 bottles..)!

January 24, 2013 - PRL with Paul Evans' group published

Field-Dependent Domain Distortion and Interlayer Polarization Distribution in PbTiO3/SrTiO3 Superlattices
P. Chen, M.P. Cosgriff, Q. Zhang, S.J. Callori, B.W. Adams, E.M. Dufresne, M. Dawber, and P.G. Evans
Phys. Rev. Lett. 110, 047601 (2013).

January 23, 2013 - Kevin Chen, Intel finalist

Congratulations to Kevin who today was named as a finalist in the Intel Science Talent Search for the work he did in our group this summer!

January 10th, 2013 - Intel Semifinalists

Both Grace Pan and Kevin Chen were today named as semifinalists in the Intel Science Talent Search for the work they did in our group over the summer. Congratulations to them both, and thanks to Sara and John who helped them get started with their projects!

December 13, 2012 - Congratulations Dr John!

John Sinsheimer defended his thesis today to become the first PhD graduate from our group. John will start as a postdoc at Brookhaven National Laboratory in January. Congratulations to John on his excellent thesis!

October 19, 2012 - Grace is Siemens Semifinalist

Congratulations to Grace Pan who was named a Siemens semifinalist today for the work she did with us this summer!

October 17, 2012 - Polarization rotation PRL is out!

Engineering polarization rotation in a ferroelectric superlattice
J. Sinsheimer, S.J. Callori, B. Bein, Y. Benkara, J. Daley, J. Coraor, D. Su, P.W. Stephens, and M. Dawber
Phys. Rev. Lett 109, 167601 (2012).

A key property that drives research in ferroelectric perovskite oxides is their strong piezoelectric response in which an electric field is induced by an applied strain, and vice-versa for the converse piezoelectric effect. We have achieved an experimental enhancement of the piezoelectric response and dielectric tunability in artificially layered epitaxial PbTiO3/CaTiO3 superlattices through an engineered rotation of the polarization direction. As the relative layer thicknesses within the superlattice were changed from sample to sample we found evidence for polarization rotation in multiple x-ray diffraction measurements. Associated changes in functional properties were seen in electrical measurements and piezoforce microscopy. The results demonstrate a new approach to inducing polarization rotation under ambient conditions in an artificially layered thin film.

This paper is also available on the arXiv at http://arxiv.org/abs/1209.3227.

August 10th 2012 - Simons Posters

Grace and Kevin both presented excellent posters at the closing ceremony of this year's Simons program. We will miss them both!

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August 9th 2012 - PTO/SRO PRL is out

Ferroelectric PbTiO3/SrRuO3 superlattices with broken inversion symmetry
S.J. Callori, J. Gabel, D. Su, J. Sinsheimer, M.V. Fernandez-Serra, M. Dawber
Phys. Rev. Lett. 109, 067601 (2012)

July 18th 2012: Lukas defends his Master's thesis

Lukas Kuerten has successfully defended his Master's thesis on “Observation of natural domain structure in ferroelectric superlattices by Piezoresponse Force Microscopy”. Look out for a preprint on this topic soon!

July 3rd 2012

Our paper on PTO/SRO superlattices has been accepted for publication in Physical Review Letters!

June 4th 2012

Matt has written a viewpoint in Physics on the interesting discovery of a material in which electronic ferroelectricity is opposed to, and overpowers, ionic ferroelectricity.

The viewpoint can be found here and the Phys. Rev. Lett. paper it describes can be found here.

January 25 2012: Update!

Juli Coraor has been named as a finalist in the Intel Science Talent Search and will go to Washington DC in March to compete with the top 40 students from the nearly 2000 who entered. Congratulations to Juli!

January 2012: Paper on PTO/SRO superlattices posted to the arXiv

Ferroelectric PbTiO3/SrRuO3 superlattices with broken inversion symmetry

S.J. Callori, J. Gabel, D. Su, J. Sinsheimer, M.V. Fernandez-Serra, M. Dawber

We have fabricated PbTiO3/SrRuO3 superlattices with ultra-thin SrRuO3 layers. Due to the superlattice geometry, the samples show a large anisotropy in their electrical resistivity, which can be controlled by changing the thickness of the PbTiO3 layers. Therefore, along the ferroelectric direction, SrRuO3 layers can act as dielectric, rather than metallic, elements. We show that, by reducing the concentration of PbTiO3, an increasingly important effect of polarization asymmetry due to compositional inversion symmetry breaking occurs. The results are significant as they represent a new class of ferroelectric superlattices, with a rich and complex phase diagram. By expanding our set of materials we are able to introduce new behaviors that can only occur when one of the materials is not a perovskite titanate. Here, compositional inversion symmetry breaking in bi-color superlattices, due to the combined variation of A and B site ions within the superlattice, is demonstrated using a combination of experimental measurements and first principles density functional theory.

A preprint of this paper is available on the arXiv at http://arxiv.org/abs/1201.2893

January 2012: Juli Coraor recognized for her research with our group

Congratulations to Juli Coraor for being named as a semifinalist in both the Intel and Siemens Science competitions! Juli is a high school senior at Huntington High School. She was a Simons Summer Research fellow in the summer of 2011 and continues to be actively involved with our group.

December 2010: Group Christmas Party

June 2010: The group has plenty of camera phones..

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December 2009: Beamtime at Swiss Light Source (and Rostiland)

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August 2009: Benedikt completes his Master's thesis...

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July 2009: Nice PTO/BTO superlattices in production

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May 2009: Asylum MFP-3D AFM installed

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March 2009: X-ray diffraction during film growth at NSLS X21

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February 2009: We are making films!

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29 September 2008: X-rays operational, deposition on line soon!

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3 July 2008: John and Sara measure their first hysteresis loops (using a system they built)

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9 June 2008: Special Issue of Journal of Physics: Condensed Matter on Oxide Surfaces

10 April 2008: Nature paper on improper ferroelectricity in superlattices is out!

Improper ferroelectricity in perovskite oxide artificial superlattices
E. Bousquet, M. Dawber, N. Stucki, C. Lichtensteiger, P. Hermet, S.Gariglio, J.-M. Triscone, and P. Ghosez
Nature, 452, 732 (2008).

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5 February 2008: The lab space is empty, painted and ready to go!

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Last modified: 2013/09/23 17:18