Atomically Thin Stacks of Polar Insulators: A Route to Atomic-Scale Multiferroics

The continuous demand for smaller electronic components is forcing industry to consider devices at the atomic scale. One of the side effects of size reduction in electronic devices is the appearance of quantum effects, which preclude engineers from simply scaling down the functionality of existing components. In the case of data storage, different approaches have been followed to increase of information density, for instance a reduction of the physical bit size or a combination of different properties (like magnetic and ferroelectric) to achieve more than two states in which to store data. Nonetheless, combining ferroelectric and magnetic properties has been difficult since there is a contra-indication between the conventional mechanism for cation off-centring in ferroelectrics and the formation of magnetic moments. Moreover, the observation of ferroelectric and magnetoelectric effects at the atomic scale has remained difficult due to physical constraints. Using scanning tunnelling microscopy and spectroscopy we study the effects of stacking sodium chloride bilayer and monolayer (NaCl), that is, an atomically thin ionic insulator, on top of copper nitride (Cu2N), which is another atomically thin insulating layer. We observe that NaCl exhibits inverse piezoelectric behaviour - displacement of the atoms driven by an applied electric field – that can reverse electric dipole orientations. Small detected hysteresis suggests that is an incipient ferroelectric behaviour, further confirmed when the same experiment is performed on top of defects of the NaCl layer, where the dipole reversal is pinned and the ferroelectric cycle broadened. Combined capabilities of the microscope – single atom evaporation and high energy resolution – allow us to study spin excitation of single magnetic impurities when adsorbed on certain substrates. Co atoms adsorbed on top of NaCl defects give us the chance to perform inelastic electron tunnelling spectroscopy (IETS) and ferroelectric cycles at the same time; with this, we observe a change in the magnetic excitation spectrum as a function of the polarization state of the supporting substrate. These results suggest a new way to create piezoelectric effects at the interface between ultra-thin insulating polar materials near conducting electrodes, pushing the feasible size of functional polar materials down to the atomic scale. Incipient ferroelectric manifestations in combination with STM capabilities allow us to study the fundamental interactions between magnetocrystalline anisotropy, magnetic moment and electric polarization, providing in practice the proof of concept of a multiferroic device at the atomic scale

Hierarchical basic zeolites allow for the solvent-free synthesis of chromene derivatives

The successful synthesis of 2-amino-chromene with excellent yields (82%) was achieved by utilizing basic hierarchical zeolites prepared by surfactant-templating as catalysts in a multicomponent reaction under solvent-free conditions. The use of these hierarchical zeolites more than doubles the activity of their microporous counterparts. These results highlight the superior diffusivity and performance of hierarchical zeolites, which can be attributed to their well-developed intracrystalline mesoporosity, highly accessible and strong basic sites.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 872102. The authors thank the Spanish Ministry of Science and Innovation and AEI/FEDER, UE for funding through the project ref. PID2021-128761OB-C21. M.J.M. thanks the Generalitat Valenciana for a PhD fellowship (GRISOLIAP/2020/165)

New project innovativeness: The case of Portuguese financial services

Services marketing literature has a tendency to perceive new services as generic and easily imitable. This paper examines the relationship of new services performance determinants (strategic/environment) from the application of a generic model. In particular, we investigate the degree of discontinuity of new projects(innovativeness to market/firm) impacts upon different levels of performance (financial/no-financial). The results of binary logistic regression analysis suggest that the factors that discern best-high marginal success is slightly different, and even lessened, than those that discern successful from unsuccessful innovations. Univariate analysis of variance indicates that there is a significant individual/interactions effect from new product innovativeness (to market/firm)

Are 'STEM from Mars and SSH from Venus'?: Challenging disciplinary stereotypes of research's social value

There is a reasonably settled consensus within the innovation community that science, technology, engineering and mathematics (STEM) research is more 'useful' to societies than other types of research, notably social sciences and humanities (SSH) researchOlmos-Peñuela, J.; Benneworth, P.; Castro-Martinez, E. (2014). Are 'STEM from Mars and SSH from Venus'?: Challenging disciplinary stereotypes of research's social value. Science and Public Policy. 41(3):384-400. doi:10.1093/scipol/sct071S384400413Abreu, M., & Grinevich, V. (2013). The nature of academic entrepreneurship in the UK: Widening the focus on entrepreneurial activities. Research Policy, 42(2), 408-422. doi:10.1016/j.respol.2012.10.005Alrøe, H. F., & Kristensen, E. S. (2002). Agriculture and Human Values, 19(1), 3-23. doi:10.1023/a:1015040009300Azagra-Caro, J. M. (2007). What type of faculty member interacts with what type of firm? Some reasons for the delocalisation of university–industry interaction. Technovation, 27(11), 704-715. doi:10.1016/j.technovation.2007.05.003Bonaccorsi, A., & Piccaluga, A. (1994). A theoretical framework for the evaluation of university-industry relationships. R&D Management, 24(3), 229-247. doi:10.1111/j.1467-9310.1994.tb00876.xBullen *, E., Robb, S., & Kenway, J. (2004). ‘Creative destruction’: knowledge economy policy and the future of the arts and humanities in the academy1. Journal of Education Policy, 19(1), 3-22. doi:10.1080/0268093042000182609Cohen, W. M., Nelson, R. R., & Walsh, J. P. (2002). Links and Impacts: The Influence of Public Research on Industrial R&D. Management Science, 48(1), 1-23. doi:10.1287/mnsc.48.1.1.14273D’Este, P., & Patel, P. (2007). University–industry linkages in the UK: What are the factors underlying the variety of interactions with industry? Research Policy, 36(9), 1295-1313. doi:10.1016/j.respol.2007.05.002Donovan, C. (2005). The Governance of Social Science and Everyday Epistemology. Public Administration, 83(3), 597-615. doi:10.1111/j.0033-3298.2005.00464.xEdgar, A., & Pattison, S. (2006). Need humanities be so useless? Justifying the place and role of humanities as a critical resource for performance and practice. Medical Humanities, 32(2), 92-98. doi:10.1136/jmh.2006.000226Geuna, A., & Muscio, A. (2009). The Governance of University Knowledge Transfer: A Critical Review of the Literature. Minerva, 47(1), 93-114. doi:10.1007/s11024-009-9118-2Gulbrandsen, M., & Kyvik, S. (2010). Are the concepts basic research, applied research and experimental development still useful? An empirical investigation among Norwegian academics. Science and Public Policy, 37(5), 343-353. doi:10.3152/030234210x501171Hessels, L. K., van Lente, H., & Smits, R. (2009). In search of relevance: the changing contract between science and society. Science and Public Policy, 36(5), 387-401. doi:10.3152/030234209x442034Jaaniste, L. (2009). Placing the creative sector within innovation: The full gamut. Innovation, 11(2), 215-229. doi:10.5172/impp.11.2.215Kaiser, R., & Prange-Gstöhl, H. (2010). A paradigm shift in European R&D policy? The EU Budget Review and the economic crisis. Science and Public Policy, 37(4), 253-265. doi:10.3152/030234210x496655Kyvik, S. (1994). Popular science publishing. Scientometrics, 31(2), 143-153. doi:10.1007/bf02018557Kyvik, S. (2005). Popular Science Publishing and Contributions to Public Discourse among University Faculty. Science Communication, 26(3), 288-311. doi:10.1177/1075547004273022Leisyte, L., & Horta, H. (2011). Introduction to a special issue: Academic knowledge production, diffusion and commercialization: policies, practices and perspectives. Science and Public Policy, 38(6), 422-424. doi:10.3152/030234211x12960315267697Molas-Gallart, J., & Tang, P. (2011). Tracing «productive interactions» to identify social impacts: an example from the social sciences. Research Evaluation, 20(3), 219-226. doi:10.3152/095820211x12941371876706Nightingale, P., & Scott, A. (2007). Peer review and the relevance gap: ten suggestions for policy-makers. Science and Public Policy, 34(8), 543-553. doi:10.3152/030234207x254396Pavitt, K. (1991). What makes basic research economically useful? Research Policy, 20(2), 109-119. doi:10.1016/0048-7333(91)90074-zPerkmann, M., & Walsh, K. (2007). University–industry relationships and open innovation: Towards a research agenda. International Journal of Management Reviews, 9(4), 259-280. doi:10.1111/j.1468-2370.2007.00225.xPilegaard, M., Moroz, P. W., & Neergaard, H. (2010). An Auto-Ethnographic Perspective on Academic Entrepreneurship: Implications for Research in the Social Sciences and Humanities. Academy of Management Perspectives, 24(1), 46-61. doi:10.5465/amp.2010.50304416Schartinger, D., Rammer, C., Fischer, M. M., & Fröhlich, J. (2002). Knowledge interactions between universities and industry in Austria: sectoral patterns and determinants. Research Policy, 31(3), 303-328. doi:10.1016/s0048-7333(01)00111-1Spaapen, J., & van Drooge, L. (2011). Introducing «productive interactions» in social impact assessment. Research Evaluation, 20(3), 211-218. doi:10.3152/095820211x12941371876742Van Langenhove, L. (2012). Make social sciences relevant. Nature, 484(7395), 442-442. doi:10.1038/484442

Computational study of Mn-doped GaN polar and non-polar surfaces

First-principles calculations were carried out in order to study the magnetic, electronic and structural properties of the Mn-doped polar GaN(0 0 0 1) and non-polar GaN(101¯0) and GaN(112¯0) surfaces, with the aim of refining the growth of thin films of this material. The results indicate that the surfaces present magnetization of approximately 4.0 μβ/Mn atom, in agreement with the recently reported theoretical and experimental results. Calculations of surface formation energy indicate that Mn atoms are incorporated into top surface layers (first and second) of GaN, being the MnGa incorporation in the polar surface more energetically favourable than in the nonpolar surfaces. In addition, it was observed that the magnetic coupling between the Mn impurities depends on the surface orientation, which could be useful for the design of magnetic nanodevices

The Moyal bracket and the dispersionless limit of the KP hierarchy

A new Lax equation is introduced for the KP hierarchy which avoids the use of pseudo-differential operators, as used in the Sato approach. This Lax equation is closer to that used in the study of the dispersionless KP hierarchy, and is obtained by replacing the Poisson bracket with the Moyal bracket. The dispersionless limit, underwhich the Moyal bracket collapses to the Poisson bracket, is particularly simple.Comment: 9 pages, LaTe

In vivo imaging enables high resolution preclinical trials on patients' leukemia cells growing in mice.

Xenograft mouse models represent helpful tools for preclinical studies on human tumors. For modeling the complexity of the human disease, primary tumor cells are by far superior to established cell lines. As qualified exemplary model, patients' acute lymphoblastic leukemia cells reliably engraft in mice inducing orthotopic disseminated leukemia closely resembling the disease in men. Unfortunately, disease monitoring of acute lymphoblastic leukemia in mice is hampered by lack of a suitable readout parameter