John Plummer

Is metallic glass poised to come of age

There have been a number of attempts to commercialize bulk metallic glass over the past 20 years. William L. Johnson, the Mettler Professor of Materials Science at California Institute of Technology, has been a prominent figure in these efforts and gives Nature Materials his perspective on the topic.

Metallurgy is key

Metallurgy has been crucial to the development of China and its economy. Ke Lu, director of the Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, talks to Nature Materials about the outlook for metallurgy and materials science in China.

Understanding a way to fly high.

David Rugg is the Senior Engineering Fellow in Materials at Rolls-Royce plc. He talks to Nature Materials about the need to understand scientific fundamentals to develop reliable and high-performance materials for jet engines, and the importance of university collaborations.

Nanoporous gold: Single crystals

Frustrated antiferromagnetic interactions occur in materials where, due to the lattice geometry, the atomic spins cannot simultaneously minimize the energies of their local interactions. For instance, if the spins are arranged in an equilateral triangle, two of them can be antiferromagnetically coupled, yet the third cannot be similarly coupled to the other two simultaneously. This situation is found in antiferromagnetic materials with kagome lattices. The exact nature of the ground state of these materials — or minimum energy state, achievable by cooling them down — has been under debate. Now, Mingxuan Fu and colleagues report experimental evidence based on nuclear magnetic resonance and magnetic susceptibility characterization, showing that the ground state of the kagome antiferromagnet ZnCu3(OH)6Cl2 is a disordered state — namley, a spin-1/2 spin liquid — with a finite gap between this and the excited states. These results clarify the fundamental issue of the ground state of these frustrated antiferromagnets and open up the possibility of experimentally studying this quantum state. DC

Graphene: Hierarchical fibres

When it comes to the reconstitution of the multicellular architecture of 3D tissues, most culture methods provide limited control over long-range tissue organization. 3D-printing and cell-patterning techniques, such as dielectrophoresis and micromoulding, often have low cell viability and resolution, or suffer from limitations in the solvent conditions and type of extracellularmatrix formulations that can be used. Zev Gartner and colleagues now show how cells and template substrates patterned with complementary DNA can be used to program specific and reversible cell adhesion layer by layer to rapidly build organoid-like microtissues with pre-defined size (up to a few centimetres long), shape and composition, and with control over the tissue’s 3D structure with single-cell resolution. Using this modular platform, the researchers built microtissues that combined various cell types with high viability to study the effects of spatial heterogeneity, composition of the extracellular matrix, and tissue shape and size on collective cell behaviour. PP CATALYSIS Pinpointing platinum Science 350, 189–192 (2015)