Table of contents



The interface is still the device p91


Oxide materials show an amazing variety of electronic and ionic phenomena. However, despite considerable advances in understanding and utilizing these effects, experimental and theoretical challenges still need to be addressed before the promised applications can be realized.



Whither the oxide interface pp92 - 94

J. Chakhalian, A. J. Millis & J. Rondinelli


Interfaces formed by transition-metal oxide materials offer a tremendous opportunity for fundamental as well as applied research. Yet, as exciting as these opportunities are, several challenges remain.


News and Views

Photonics: Stretching silicon's potential pp96 - 97

Clemens Schriever & Ralf B. Wehrspohn


The application of inhomogeneous strain to silicon photonic structures may lead to new optically active devices based on second-order nonlinear processes.

See also: Article by Cazzanelli et al.

Colloidal friction: Kinks in motion pp97 - 98

Andrea Vanossi & Erio Tosatti


The ability of laser interference potentials to trap and control colloidal particles opens up a new potential area of 'toy systems' displaying real physics. A beautiful example is the study of friction between colloidal crystals and a variety of artificially created surface potentials.

See also: Letter by Bohlein et al.

Wetting dynamics: Adsorbed colloids relax slowly pp99 - 100

Ignacio Pagonabarraga


For colloidal particles adsorbed at liquid/liquid interfaces, it is now found that the height of a particle above the interface equilibrates much more slowly than expected. Such a slow relaxation has major implications for the understanding of effective interactions between colloids at fluid interfaces.

See also: Letter by Kaz et al.

Solar-fuel generation: Towards practical implementation pp100 - 101

Søren Dahl & Ib Chorkendorff


Limiting reliance on non-renewable fossil fuels inevitably depends on a more efficient utilization of solar energy. Materials scientists discuss the most viable approaches to produce high-energy-density fuels from sunlight that can be implemented in existing infrastructures.

Material witness: Breaking the mould p102

Philip Ball




Emergent phenomena at oxide interfaces pp103 - 113

H. Y. Hwang, Y. Iwasa, M. Kawasaki, B. Keimer, N. Nagaosa & Y. Tokura


From magnetism, ferroelectricity and superconductivity to electrical and thermal properties, oxides show a broad range of phenomena of fundamental as well as practical relevance. Reviewed here are the emergent phenomena arising at the interface between oxide materials, which have attracted considerable interest based on advances in thin-film deposition techniques.

Subject terms: Electronic materials | Magnetic materials | Superconductors | Surface and thin films



Atomic-scale transport in epitaxial graphene pp114 - 119

Shuai-Hua Ji, J. B. Hannon, R. M. Tromp, V. Perebeinos, J. Tersoff & F. M. Ross


A local atom probe has been used to study the transport properties of graphene, revealing the different effects of surface steps and changes in layer thickness on substrates. Understanding the details of the defect-induced degradation of transport properties is essential for improving the efficiency of devices.

Subject terms: Electronic materials | Nanoscale materials

Synthesis of monolithic graphene–graphite integrated electronics pp120 - 125

Jang-Ung Park, SungWoo Nam, Mi-Sun Lee & Charles M. Lieber


One of the interesting features of graphene is that its properties change with the number of layers. A procedure to create monolithic devices with elements made out of different numbers of graphene layers is now shown, and a practical demonstration of this method is given by realizing transistor arrays with chemical-sensing functionalities.

Subject terms: Electronic materials | Nanoscale materials

Observation of kinks and antikinks in colloidal monolayers driven across ordered surfaces pp126 - 130

Thomas Bohlein, Jules Mikhael & Clemens Bechinger


The frictional properties of a two-dimensional colloidal crystal reveal that excitations known as kinks and antikinks form when the crystal is dragged along a solid surface. This phenomenon, which was predicted previously but never observed, demonstrates the potential of using colloidal crystals to study frictional properties that are otherwise difficult to characterize.

Subject terms: Colloids | Mechanical properties | Nanoscale materials

See also: News and Views by Vanossi & Tosatti

Self-assembly of uniform polyhedral silver nanocrystals into densest packings and exotic superlattices pp131 - 137

Joel Henzie, Michael Grünwald, Asaph Widmer-Cooper, Phillip L. Geissler & Peidong Yang


Highly monodisperse silver polyhedral nanocrystals passivated with polymers are shown to behave as quasi-hard particles that self-assemble by sedimentation into millimetre-sized supercrystals, which correspond to the particles' three-dimensional densest packings. Monte Carlo simulations confirm the observed self-assembled structures, including an exotic structure for octahedra that is stabilized by depletion forces induced by an excess of polymer in solution.

Subject terms: Colloids | Computation, modelling and theory

Physical ageing of the contact line on colloidal particles at liquid interfaces pp138 - 142

David M. Kaz, Ryan McGorty, Madhav Mani, Michael P. Brenner & Vinothan N. Manoharan


Colloidal particles adsorbed at liquid interfaces are commonly assumed to be at equilibrium, but holographic microscopy experiments now reveal that microspheres bound to a water/oil interface may take months to equilibrate. The observed ageing dynamics agree with a model of thermally activated hopping of the particle/interface contact line over nanoscale surface defects, and have implications for understanding the interactions between adsorbed colloidal particles.

Subject terms: Colloids | Computation, modelling and theory

See also: News and Views by Pagonabarraga



Electron spin coherence exceeding seconds in high-purity silicon pp143 - 147

Alexei M. Tyryshkin, Shinichi Tojo, John J. L. Morton, Helge Riemann, Nikolai V. Abrosimov, Peter Becker, Hans-Joachim Pohl, Thomas Schenkel, Michael L. W. Thewalt, Kohei M. Itoh & S. A. Lyon


The coherence lifetime of a material system to be used in quantum information protocols has to be long enough for several quantum operations to occur before the system loses its quantum coherence. The spins of impurities in silicon have been shown to have coherence lifetimes up to tens of milliseconds, but now all records are beaten with those in high-purity silicon reaching a few seconds.

Subject terms: Semiconductors | Optical, photonic and optoelectronic materials

Second-harmonic generation in silicon waveguides strained by silicon nitride pp148 - 154

M. Cazzanelli, F. Bianco, E. Borga, G. Pucker, M. Ghulinyan, E. Degoli, E. Luppi, V. Véniard, S. Ossicini, D. Modotto, S. Wabnitz, R. Pierobon & L. Pavesi


Photonic devices on silicon offer the benefit of combining advanced electronic functionality with the high bandwidth of silicon photonics. Now, efficient second-order nonlinear activity in silicon waveguides strained by a silicon nitride top layer considerably advances the potential of all-optical data management on a silicon platform.

Subject terms: Electronic materials | Semiconductors | Optical, photonic and optoelectronic materials

See also: News and Views by Schriever & Wehrspohn

High electrochemical activity of the oxide phase in model ceria–Pt and ceria–Ni composite anodes pp155 - 161

William C. Chueh, Yong Hao, WooChul Jung & Sossina M. Haile


A key step in fuel-cell energy-conversion processes is electro-oxidation of the fuel at the anode, but ways to improve electrocatalytic activity remain unclear. Using ceria–metal structures, H2-oxidation reactions are shown to be dominated by electrocatalysis at the oxide/gas interface with minimal contributions from the oxide/metal/gas triple-phase boundaries.

Subject terms: Catalytic materials | Materials for energy

Morphological instability leading to formation of porous anodic oxide films pp162 - 166

Kurt R. Hebert, Sergiu P. Albu, Indhumati Paramasivam & Patrik Schmuki


Electrochemical oxidation of metals produces anodic oxides with highly regular arrangements of pores; however, the mechanisms of pore initiation and self-ordering are not well understood. Now, a quantitative analysis method is proposed that examines the roles of oxide dissolution and ionic conduction in the morphological stability of anodic oxide films.

Subject terms: Porous materials | Surface and thin films

H-atom relay reactions in real space pp167 - 172

T. Kumagai, A. Shiotari, H. Okuyama, S. Hatta, T. Aruga, I. Hamada, T. Frederiksen & H. Ueba


The relay mechanism in which hydrogen atom transfer occurs along hydrogen bonds plays a crucial role in many functional compounds. Using a scanning tunnelling microscope, the transfer of hydrogen atoms along hydrogen-bonded chains assembled on a Cu(110) surface is shown to be controllable and reversible.

Subject terms: Surface and thin films | Characterisation and analytical techniques | Computation, modelling and theory



Li–O2 and Li–S batteries with high energy storage p172

Peter G. Bruce, Stefan A. Freunberger, Laurence J. Hardwick & Jean-Marie Tarascon


See also: Review by Bruce et al.