Nature Materials contents: August 2013 Volume 12 Number 8 pp 681-771

Advertisement How to maximise nanopatterning performance of your FIB-SEM? Visit Raith and learn how ELPHY's MultiBeam's FLEXposure™ patterning modes improve FIB-SEM lithography. TABLE OF CONTENTS August 2013 Volume 12, Issue 8 Editorial Commentary Interview Research Highlights News and Views Letters Articles Subscribe   Facebook   RSS   Recommend to library   Twitter   Advertisement New Impact Factor The new impact factor for Nature Materials is 35.749*. This places the journal first in 4 categories: Materials Science, Multidisciplinary; Physics Applied; Chemistry, Physical and Physics, Condensed Matter.  *2012 Journal Citation Reports® (Thomson Reuters, 2013)   Editorial Top The road ahead for research in Greece   p681 doi:10.1038/nmat3735 Underfunding, chronic structural deficiencies and lack of proper evaluation are acutely harming Greek science. The only way forward is to increase investment in human capital and infrastructure, coupled with organizational reforms and a change of government attitude towards research. Commentary Top Greece in crisis   pp683 - 685 Costas M. Soukoulis doi:10.1038/nmat3727 In spite of substantial progress over the past 35 years, underfunding and lack of evaluation are preventing Greek research and technology from reaching its true potential. A coordinated effort between government, academia and industry could lead to viable solutions to the current crisis. Interview Top Tough times for Greek science   pp686 - 687 doi:10.1038/nmat3726 The recent economic crisis has drastically affected research and development in Greece, but competitive research goes on, says Eleftherios Economou, a founder of the Foundation of Research and Technology Hellas (FORTH) research centre in Greece, and former General Secretary for research and technology. Research Highlights Top Multifunctional graphene | Multiplexed for detection | Branches reduce blinking | Cool MOFs | Coherent absorption in graphene News and Views Top Nanotwinned metals: It's all about imperfections   pp689 - 690 Julia R. Greer doi:10.1038/nmat3721 Experiments and simulations show that coherent twin boundaries, commonly believed to be perfect, are riddled with kinks and other defects. See also: Letter by Wang et al. Valleytronics: Electrons dance in diamond   pp690 - 691 Christoph E. Nebel doi:10.1038/nmat3724 In addition to manipulating the charge or spin of electrons, another way to control electric current is by using the 'valley' degree-of-freedom of electrons. The first demonstration of the generation, transport and detection of valley-polarized electrons in bulk diamond now opens up new opportunities for quantum control in electronic devices. See also: Article by Isberg et al. Quasicrystals: Model structures   pp692 - 693 Marc de Boissieu doi:10.1038/nmat3725 Elucidating the relationship between the structure and magnetism of quasicrystals has long been a challenge. The discovery of an extended family of binary icosahedral quasicrystals with localized magnetic moments may be an important step in shedding light on this issue. See also: Letter by Goldman et al. Macromolecular mixing: Entropic templating   pp693 - 694 Igal Szleifer doi:10.1038/nmat3728 The entropic repulsion between tethered molecular brushes at fluid interfaces templates the mixing of otherwise incompatible macromolecules. See also: Letter by Sheiko et al. Nanoparticle self-assembly: Bonding them all   pp694 - 696 Ulrich Simon doi:10.1038/nmat3715 A general approach for decorating nanoparticles with a highly dense shell of DNA linkers expands the range of building blocks that can be used for DNA-mediated nanoparticle self-assembly. See also: Letter by Zhang et al. Material witness: Colloids get active   p696 Philip Ball doi:10.1038/nmat3720 Nature Materials JOBS of the week PhD: Electronic Properties Of Novel Low-Dimensional Materials Istituto Italiano di Tecnologia - Italian Institute of Technology Three Professor Positions in Materials Chemistry Eindhoven University of Technology (TU / e) Full Professor in Inorganic Materials Chemistry University of Bern - Department of Chemistry & Biochemistry PhD Hybrid Nanostructures Optics / Plasmonics Istituto Italiano di Tecnologia - Italian Institute of Technology Associate Professor, Assistant Professor and Postdoctoral Researcher Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology More Science jobs from Nature Materials EVENT From Carbon-Rich Molecules to Carbon-Based Materials 22.09.13 Casablanca, Morocco More science events from Letters Top Defective twin boundaries in nanotwinned metals   pp697 - 702 Y. Morris Wang, Frederic Sansoz, Thomas LaGrange, Ryan T. Ott, Jaime Marian, Troy W. Barbee, Jr & Alex V. Hamza doi:10.1038/nmat3646 Coherent twin boundaries, which usually form during the growth, deformation or annealing of crystalline solids, are widely described as perfect interfaces. Experiments and simulations now show that as-grown coherent twin boundaries in nanotwinned copper consist of incoherent segments and partial dislocations, and significantly affect the material’s mechanical behaviour and deformation mechanisms. See also: News and Views by Greer Titanium dxy ferromagnetism at the LaAlO3/SrTiO3 interface   pp703 - 706 J.-S. Lee, Y. W. Xie, H. K. Sato, C. Bell, Y. Hikita, H. Y. Hwang & C.-C. Kao doi:10.1038/nmat3674 Results suggesting the onset of magnetism at the interface between LaAlO3 and SrTiO3 have been among the more intriguing associated with this system. Using element-specific techniques such as X-ray magnetic circular dichroism, direct signatures of in-plane ferromagnetic order occurring at the interface are now reported. Imaging the evolution of metallic states in a correlated iridate   pp707 - 713 Yoshinori Okada, Daniel Walkup, Hsin Lin, Chetan Dhital, Tay-Rong Chang, Sovit Khadka, Wenwen Zhou, Horng-Tay Jeng, Mandar Paranjape, Arun Bansil, Ziqiang Wang, Stephen D. Wilson & Vidya Madhavan doi:10.1038/nmat3653 Iridate materials are at present the focus of interest because the combination of strong spin–orbit effects and many-body electronic correlations makes their physics non-trivial. Now, the density of states of Sr3Ir2O7 is mapped out spatially using scanning tunnelling microscopy and spectroscopy, yielding insights into the influence of nanoscale heterogeneities on the electronic structure. A family of binary magnetic icosahedral quasicrystals based on rare earths and cadmium    pp714 - 718 Alan I. Goldman, Tai Kong, Andreas Kreyssig, Anton Jesche, Mehmet Ramazanoglu, Kevin W. Dennis, Sergey L. Bud'ko & Paul C. Canfield doi:10.1038/nmat3672 At present, there are no known examples of binary icosahedral quasicrystals featuring localized magnetic moments. Now, a family of magnetic binary icosahedral quasicrystals is discovered, offering the possibility of studying the behaviour of coupled magnetic interactions in the presence of aperiodic structural order. See also: News and Views by de Boissieu Engineered doping of organic semiconductors for enhanced thermoelectric efficiency   pp719 - 723 G-H. Kim, L. Shao, K. Zhang and K. P. Pipe doi:10.1038/nmat3635 The conversion efficiency of heat to electricity in thermoelectric materials depends on both their thermopower and electrical conductivity. It is now reported that, unlike their inorganic counterparts, organic thermoelectric materials show an improvement in both these parameters when the volume of dopant elements is minimized; furthermore, a high conversion efficiency is achieved in PEDOT:PSS blends. Carbon monoxide-induced adatom sintering in a Pd–Fe3O4 model catalyst   pp724 - 728 Gareth S. Parkinson, Zbynek Novotny, Giacomo Argentero, Michael Schmid, Jiří Pavelec, Rukan Kosak, Peter Blaha & Ulrike Diebold doi:10.1038/nmat3667 Although the coarsening of catalytically active metal clusters can be accelerated by the presence of gases, the role played by gas molecules is difficult to ascertain. Carbon monoxide-induced coalescence of Pd adatoms supported on a Fe3O4 surface is now investigated at room temperature, and Pd-carbonyl species are shown to be responsible for their mobility. Core–shell strain structure of zeolite microcrystals   pp729 - 734 Wonsuk Cha, Nak Cheon Jeong, Sanghoon Song, Hyun-jun Park, Tung Cao Thanh Pham, Ross Harder, Bobae Lim, Gang Xiong, Docheon Ahn, Ian McNulty, Jungho Kim, Kyung Byung Yoon, Ian K. Robinson & Hyunjung Kim doi:10.1038/nmat3698 Understanding the distribution of internal local strains within zeolites is important for catalytic applications because they can affect the rates of adsorption and diffusion of guest molecules. A ‘triangular’ deformation-field distribution in ZSM-5 zeolites is now observed, showing the presence of a strain within the crystal that arises from the heterogeneous core–shell structure. Perfect mixing of immiscible macromolecules at fluid interfaces   pp735 - 740 Sergei S. Sheiko, Jing Zhou, Jamie Arnold, Dorota Neugebauer, Krzysztof Matyjaszewski, Constantinos Tsitsilianis, Vladimir V. Tsukruk, Jan-Michael Y. Carrillo, Andrey V. Dobrynin & Michael Rubinstein doi:10.1038/nmat3651 Surface-active macromolecules that are chemically different can be mixed at fluid interfaces if the molecules attract each other, or if they have complementary shapes and a net attraction is induced by a depletant. Now, a strategy that eludes the need for complementarity between the molecules, where tethered molecular brushes induce an entropic net repulsion between like species, achieves long-range arrays of perfectly mixed macromolecules. See also: News and Views by Szleifer A general approach to DNA-programmable atom equivalents   pp741 - 746 Chuan Zhang, Robert J. Macfarlane, Kaylie L. Young, Chung Hang J. Choi, Liangliang Hao, Evelyn Auyeung, Guoliang Liu, Xiaozhu Zhou & Chad A. Mirkin doi:10.1038/nmat3647 Progress in DNA-mediated nanoparticle self-assembly has been hampered by the lack of a general method to control the bonding of nanoparticles of different chemical composition into lattices by means of DNA linkers. An approach that makes possible the functionalization of any nanoparticle that has hydrophobic capping ligands with a dense monolayer of DNA, and allows for independent control of composition, particle size and lattice parameters for a variety of lattices, is now demonstrated. See also: News and Views by Simon Cinnamate-based DNA photolithography   pp747 - 753 Lang Feng, Joy Romulus, Minfeng Li, Ruojie Sha, John Royer, Kun-Ta Wu, Qin Xu, Nadrian C. Seeman, Marcus Weck & Paul Chaikin doi:10.1038/nmat3645 A highly selective and efficient approach to covalently bond complementary DNA strands in solution and on surfaces on demand is shown. The approach involves the substitution of a pair of complementary bases by cinnamate-based crosslinks, which can be activated on exposure to ultraviolet light, and allows chemical patterning of flat and curved surfaces down to micrometre and potentially submicrometre resolutions. Articles Top Vapour phase growth and grain boundary structure of molybdenum disulphide atomic layers   pp754 - 759 Sina Najmaei, Zheng Liu, Wu Zhou, Xiaolong Zou, Gang Shi, Sidong Lei, Boris I. Yakobson, Juan-Carlos Idrobo, Pulickel M. Ajayan & Jun Lou doi:10.1038/nmat3673 The controlled vapour phase synthesis of molybdenum disulphide atomic layers and a fundamental mechanism for the nucleation, growth and grain boundary formation in its crystalline monolayers are now reported. Using high-resolution electron microscopy imaging, the atomic structure of the grains and their boundaries in the polycrystalline molybdenum disulphide atomic layers are examined, and the primary mechanisms for grain-boundary formation are evaluated. Generation, transport and detection of valley-polarized electrons in diamond   pp760 - 764 Jan Isberg, Markus Gabrysch, Johan Hammersberg, Saman Majdi, Kiran Kumar Kovi & Daniel J. Twitchen doi:10.1038/nmat3694 Electronic devices usually rely on the charge or spin of electrons to encode information. A less exploited route is to manipulate the valley quantum number of electrons. It is now shown that the generation, macroscopic transport and detection of valley-polarized electrons in bulk diamond can be achieved with a relaxation time of 300 ns at 77 K, forming a basis for valleytronic devices. See also: News and Views by Nebel Compositional segregation in shaped Pt alloy nanoparticles and their structural behaviour during electrocatalysis   pp765 - 771 Chunhua Cui, Lin Gan, Marc Heggen, Stefan Rudi and Peter Strasser doi:10.1038/nmat3668 Although site-dependent metal surface segregation in bimetallic nanoalloys affects catalytic activity and stability, segregation on shaped nanocatalysts and their atomic-scale evolution is largely unexplored. PtxNi1−x alloy nanoparticle electrocatalysts with unique activity for oxygen reduction reactions exhibit an unexpected compositional segregation structure across the {111} facets. Top Advertisement Naturejobs presents the: Naturejobs Career Expo September 19, 2013 The Business Design Centre, London, UK  Click here for more information or to register for this conference today!   Natureevents is a fully searchable, multi-disciplinary database designed to maximise exposure for events organisers. The contents of the Natureevents Directory are now live. The digital version is available here. Find the latest scientific conferences, courses, meetings and symposia on natureevents.com. For event advertising opportunities across the Nature Publishing Group portfolio please contact natureevents@nature.com More Nature Events

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