Blog

Ablitt C, Mostofi AA, Bristowe NC and Senn MS (2018) Control of Uniaxial Negative Thermal Expansion in Layered Perovskites by Tuning Layer Thickness. Front. Chem. 6:455. doi: 10.3389/fchem.2018.00455 Uniaxial negative thermal expansion (NTE) is known to occur in low $n$ members of the An+1$BnO3n+1 Ruddlesden–Popper layered perovskite series with a frozen rotation of BO_6 octahedra about the layering axis. PreviousRead more

The Senn Group is growing – meet our new group members! Fernando joins us from Argentina on a 2 year fellowship funded by the Marie Skłodowska Curie Action and the Institute of Advanced Study of the University of Warwick,  Anna is starting her PhD in the group on a studentship part funded by the ISIS Neutron and Muon SourceRead more

Mark S. Senn and Nicolas C. Bristowe, Acta Crystallographica Section A: Foundations and Advances, 2018, Volume A74, pages 308-321 A group-theoretical approach is used to enumerate the possible couplings between magnetism and ferroelectric polarization in the parent Pm-3m perovskite structure. It is shown that third-order magnetoelectric coupling terms must always involve magnetic ordering at theRead more

Hanna L. B. Boström,  Mark S. Senn and Andrew L. Goodwin, Nature Communications (2018) 9:2380 The central goal of crystal engineering is to develop precise control over material function via rational design of structure. A particularly successful realisation of this paradigm is the example of hybrid improper ferroelectricity in layered perovskite materials, where cation vacanciesRead more

Wei-Tin Chen, Chin-Wei Wang, Hung-Cheng Wu, Fang-Cheng Chou, Hung-Duen Yang, Arkadiy Simonov, and Mark S. Senn, Phys. Rev. B 97, 144102 (2018)   There has recently been renewed interest in improper ferroelectricity due to the discovery of a “hybrid” mechanism by which two nonpolar lattice modes couple to a third polar mode. Here, the authorsRead more

At least one fully funded Royal Society PhD studentship for 4 years (UK fees and stipend) is available within the senngroup.  The project will be in the field of multiferroic materials within the broader area of research encompassed by materials chemistry,  solid state science and physical crystallography.    The start date of the PhD studentship will be October 2018, and the project will be conducted at the UniversityRead more

Chris has headed off this month for a 7 month long industrial placement at BOSCH in Boston, Massachusetts, USA.  He will be putting his PhD research on negative thermal expansion in layered Perovskites on hold during this period and applying his computational modeling skills to new challenges in an industrial lead R&D environment.  Good luck Chris, and we lookRead more

Chris Ablitt, Sarah Craddock, Mark S. Senn, Arash A. Mostofi & Nicholas C. Bristowe, npj Computational Materials 3, Article number: 44 (2017) doi:10.1038/s41524-017-0040-0   Why is it that ABO3 perovskites generally do not exhibit negative thermal expansion (NTE) over a wide temperature range, whereas layered perovskites of the same chemical family often do? It isRead more

A fully funded (3.5 years for EU/UK students) PhD studentship on understanding the microscopic mechanisms in functional materials is available within the Senn group.  The broader area of research encompasses that of solid state science and physical crystallography.    The start date of the PhD studentship will be October 2017, and the project will be conducted at the University of Warwick.  Interested applicantsRead more

Sarah Craddock, Mark S. Senn. Journal of Solid State Chemistry 248 (2017) 157–163. There has been renewed interest in the Ruddlesden-Popper phase (n=2) of composition Can+1MnnO3 n+1 in the light of recent research that has highlighted the nature of the improper ferroelectric ground state, which arises due to the couplings between specific combinations of MnO6Read more