Table of contents


Brazil

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Editorial

Ready for the best p527

doi:10.1038/nmat2801

The large investments in research and education made in recent years have provided Brazilian scientists with the conditions to achieve scientific excellence.


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Commentary

Brazilian science towards a phase transition pp528 - 531

Ado Jorio, Francisco César de Sá Barreto, José Francisco de Sampaio & Hélio Chacham

doi:10.1038/nmat2790

The historical trajectory of materials science in Brazil shows the fast establishment of a high-quality, sizeable and productive scientific community. It is now time for a change in attitude towards real innovation and excellence.


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Interview

Exciting times for Brazilian science pp532 - 533

doi:10.1038/nmat2791

Sergio Machado Rezende has served for 5 years as the Minister for Science and Technology of Brazil. Nature Materials has asked him about the past and future of science in his country.


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Research Highlights

Our choice from the recent literature p534

doi:10.1038/nmat2794


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News and Views

Regenerative medicine: Noodle gels for cells pp535 - 536

Timothy J. Deming

doi:10.1038/nmat2789

Heating and cooling of peptide amphiphile suspensions converts disorganized nanofibres into liquid-crystalline nanofibre bundles that gel on addition of salts. The noodle-shaped strings of gel can entrap and align cells.

See also: Article by Zhang et al.


Topological insulators: Starting a new family pp536 - 537

Marcel Franz

doi:10.1038/nmat2783

Ternary intermetallic Heusler compounds, originally discovered by a German mining engineer and chemist in 1903, may show exotic topological insulator behaviour unknown to science just five years ago.

See also: Letter by Chadov et al. | Letter by Lin et al.


Polymer hydrogels: Chaperoning vaccines pp537 - 538

Herman F. Staats & Kam W. Leong

doi:10.1038/nmat2788

A cationic nanosized hydrogel (nanogel) shows controlled antigen delivery in vivo following intranasal administration and hence holds promise for a clinically effective adjuvant-free and needle-free vaccine system.

See also: Letter by Nochi et al.


Material witness: Pasta physics p539

Philip Ball

doi:10.1038/nmat2793


Crystal engineering in two dimensions: Surface attraction pp539 - 540

Mark A. Green

doi:10.1038/nmat2786

A new route to layer-by-layer assembly of metal–organic framework thin films affords highly ordered and controllable surfaces with potential in chemical sensing and catalyst applications.

See also: Letter by Makiura et al.


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Letters

Tunable multifunctional topological insulators in ternary Heusler compounds pp541 - 545

Stanislav Chadov, Xiaoliang Qi, Jürgen Kübler, Gerhard H. Fecher, Claudia Felser & Shou Cheng Zhang

doi:10.1038/nmat2770

Topological insulators have been predicted and recently demonstrated experimentally in a series of binary alloys. It is now show theoretically that about 50 Heusler compounds show features similar to those of the confirmed topological insulator HgTe, which considerably expands the possibility of realizing quantum topological phenomena.

Subject Categories: Electronic materials | Molecular electronics

See also: Letter by Lin et al. | News and Views by Franz


Half-Heusler ternary compounds as new multifunctional experimental platforms for topological quantum phenomena pp546 - 549

Hsin Lin, L. Andrew Wray, Yuqi Xia, Suyang Xu, Shuang Jia, Robert J. Cava, Arun Bansil & M. Zahid Hasan

doi:10.1038/nmat2771

Topological insulators have been predicted and recently demonstrated experimentally in a series of binary alloys. It is now show theoretically that ternary half-Heusler alloys have electronic properties similar to those of the experimentally verified topological insulators, and represent a platform for observing quantum topological phenomena.

Subject Categories: Electronic materials | Molecular electronics

See also: Letter by Chadov et al. | News and Views by Franz


Observation of shell effects in superconducting nanoparticles of Sn pp550 - 554

Sangita Bose, Antonio M. García-García, Miguel M. Ugeda, Juan D. Urbina, Christian H. Michaelis, Ivan Brihuega & Klaus Kern

doi:10.1038/nmat2768

When a superconductor is shrunk to the nanoscale, quantum size effects are predicted to strongly influence superconductivity. This is now demonstrated in Sn nanoparticles in which a reduction in size leads to a substantial enhancement of the superconducting gap.

Subject Categories: Superconductors | Nanoscale materials


Dimensional crossover of thermal transport in few-layer graphene pp555 - 558

Suchismita Ghosh, Wenzhong Bao, Denis L. Nika, Samia Subrina, Evghenii P. Pokatilov, Chun Ning Lau & Alexander A. Balandin

doi:10.1038/nmat2753

The ability to propagate heat in a film should improve with increasing thickness. However, graphene has a higher thermal conductivity than graphite, despite having a smaller thickness. The crossover from two-dimensional to bulk graphite is now studied experimentally and explained theoretically. The results may pave the way to thermal management applications in nanoelectronics.

Subject Categories: Electronic materials | Molecular electronics | Nanoscale materials


An orthophosphate semiconductor with photooxidation properties under visible-light irradiation pp559 - 564

Zhiguo Yi, Jinhua Ye, Naoki Kikugawa, Tetsuya Kako, Shuxin Ouyang, Hilary Stuart-Williams, Hui Yang, Junyu Cao, Wenjun Luo, Zhaosheng Li, Yun Liu & Ray L. Withers

doi:10.1038/nmat2780

The search for active semiconductor photocatalysts that split water directly under visible-light irradiation remains challenging for solar applications. An orthophosphate semiconductor, Ag3PO4, which is capable of harnessing visible light to oxidize water as well as decompose organic contaminants in aqueous solution is now reported.

Subject Categories: Semiconductors | Materials for energy


Surface nano-architecture of a metal–organic framework pp565 - 571

Rie Makiura, Soichiro Motoyama, Yasushi Umemura, Hiroaki Yamanaka, Osami Sakata & Hiroshi Kitagawa

doi:10.1038/nmat2769

For metal–organic frameworks to be used for applications such as gas storage it is necessary to direct their assembly. Here, thin crystalline films of metal–organic frameworks are fabricated on a solid surface with structural growth control over both in-plane and out-of-plane orientations relative to the substrate.

Subject Categories: Polymers | Porous materials | Design synthesis and processing

See also: News and Views by Green


Nanogel antigenic protein-delivery system for adjuvant-free intranasal vaccines pp572 - 578

Tomonori Nochi, Yoshikazu Yuki, Haruko Takahashi, Shin-ichi Sawada, Mio Mejima, Tomoko Kohda, Norihiro Harada, Il Gyu Kong, Ayuko Sato, Nobuhiro Kataoka, Daisuke Tokuhara, Shiho Kurokawa, Yuko Takahashi, Hideo Tsukada, Shunji Kozaki, Kazunari Akiyoshi & Hiroshi Kiyono

doi:10.1038/nmat2784

Mucosal diseases are becoming more prevalent and needle-free vaccines could be instrumental in combating this. A nanometre-sized hydrogel consisting of a cationic type of cholesteryl group bearing pullulan has now been used as an intranasal vaccine-delivery system.

Subject Categories: Biological materials | Biomedical materials | Nanoscale materials

See also: News and Views by Staats & Leong


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Articles

Robust isothermal electric control of exchange bias at room temperature pp579 - 585

Xi He, Yi Wang, Ning Wu, Anthony N. Caruso, Elio Vescovo, Kirill D. Belashchenko, Peter A. Dowben & Christian Binek

doi:10.1038/nmat2785

The control of magnetic properties by electric fields is key to realizing spintronics devices. The surface of the antiferromagnetic magnetoelectric Cr2O3 is now shown to exhibit room-temperature ferromagnetism, whose direction can be switched by an electric field. This magnetization switches the exchange-bias field with magnetic multilayers grown on Cr2O3, promising a new route towards room-temperature spintronics devices.

Subject Categories: Electronic materials | Magnetic materials | Surface and thin films


Extremely long quasiparticle spin lifetimes in superconducting aluminium using MgO tunnel spin injectors pp586 - 593

Hyunsoo Yang, See-Hun Yang, Saburo Takahashi, Sadamichi Maekawa & Stuart S. P. Parkin

doi:10.1038/nmat2781

There has been an intense search in recent years for long-lived spin-polarized carriers for spintronics and quantum computing devices. It is now shown that spin-polarized quasiparticles in superconducting aluminium layers have surprisingly long spin lifetimes, nearly a million times longer than in their normal state.

Subject Categories: Superconductors | Electronic materials | Magnetic materials


A self-assembly pathway to aligned monodomain gels pp594 - 601

Shuming Zhang, Megan A. Greenfield, Alvaro Mata, Liam C. Palmer, Ronit Bitton, Jason R. Mantei, Conrado Aparicio, Monica Olvera de la Cruz & Samuel I. Stupp

doi:10.1038/nmat2778

Peptide-based molecules that self-assemble into lamellar plaques with fibrous texture on heating, subsequently break on cooling to form long-range aligned bundles of nanofibres. This thermal route to monodomain gels is compatible for living cells and allows the formation of noodle-like viscoelastic strings of any length.

Subject Categories: Liquid crystals | Biological materials | Biomedical materials | Design synthesis and processing

See also: News and Views by Deming


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