Boron atoms stretch out, gain new powers

Rice simulations demonstrate 1-D material’s stiffness, electrical versatility

Hold on, there, graphene. You might think you’re the most interesting new nanomaterial of the century, but boron might already have you beat, according to scientists at Rice University.

A Rice team that simulated one-dimensional forms of boron — both two-atom-wide ribbons and single-atom chains — found they possess unique properties. The new findings appear this week in the Journal of the American Chemical Society.

For example, if metallic ribbons of boron are stretched, they morph into antiferromagnetic semiconducting chains, and when released they fold back into ribbons.

In The News

New Wave of 2D Boron

Rice University researchers say 2-D boron may be best for flexible electronics

2d-b-waveThough they’re touted as ideal for electronics, two-dimensional materials like graphene may be too flat and hard to stretch to serve in flexible, wearable devices. “Wavy” borophene might be better, according to Rice University scientists.

The Rice lab of theoretical physicist Boris Yakobson and experimental collaborators observed examples of naturally undulating, metallic borophene, an atom-thick layer of boron, and suggested that transferring it onto an elastic surface would preserve the material’s stretchability along with its useful electronic properties.

Highly conductive graphene has promise for flexible electronics, Yakobson said, but it is too stiff for devices that also need to stretch, compress or even twist. But borophene deposited on a silver substrate develops nanoscale corrugations. Weakly bound to the silver, it could be moved to a flexible surface for use.

The research appears this month in the American Chemical Society journal Nano Letters.

In The News

Polyphony in B flat

At last, experiments offer two-dimensional boron… on a silver platterb_cards

In an extensive “News & Views” in Nature Chemistry, we provide a critical view of the latest breakthrough in materials flatland: the synthesis of two-dimensional boron. It also reflects on a decade-long effort in Yakobson’s group towards understanding and eventually predicting the structure of low-dimensional boron: from the B80 fullerene, to the polymorphism of 2D boron, to practical routes for its synthesis.

Can Two-Dimensional Boron Superconduct?

Rice University scientists predict 2-D material – no longer theoretical – has unique propertiesimg4news_small

Rice University scientists have determined that two-dimensional boron is a natural low-temperature superconductor. In fact, it may be the only 2-D material with such potential.

Rice theoretical physicist Boris Yakobson and his co-workers published their calculations that show atomically flat boron is metallic and will transmit electrons with no resistance. The work appears this month in the American Chemical Society journal Nano Letters.

The hitch, as with most superconducting materials, is that it loses its resistivity only when very cold, in this case between 10 and 20 kelvins (roughly, minus-430 degrees Fahrenheit). But for making very small superconducting circuits, it might be the only game in town.

– See more at Rice News

2D Boron among the Angew. Chem. covers


Two-dimensional boron would take different forms, depending on the substrate used in chemical vapor deposition growth. Image by Zhuzha Zhang

Our most recent work on 2D boron will be featured on a cover of the upcoming issue of Angewandte Chemie International Edition. The study builds on two of our previous works on two-dimensional boron [1, 2]  and provides further clues as to how this elusive material can be synthesized and what the product may look like.

Calculation of the atom-by-atom energies involved in creating a sheet of boron revealed that the metal substrate – the surface upon which two-dimensional materials are grown in a chemical vapor deposition (CVD) furnace – would make all the difference.

The new calculations show it may be possible to guide the formation of 2D boron by tailoring boron-metal interactions.Theoretical physicist Boris Yakobson and his Rice colleagues discovered that copper, a common substrate in graphene growth, might be best to obtain flat boron, while other metals would guide the resulting material in their unique ways.

Y. Liu, E. S. Penev, B. I. Yakobson, Probing the Synthesis of Two-Dimensional Boron by First-Principles Computations. Angew. Chem. Int. Ed. 52, 3156–3159 (2013).
E. S. Penev, S. Bhowmick, A. Sadrzadeh, B. I. Yakobson, Polymorphism of Two-Dimensional Boron. Nano Lett. 12, 2441–2445 (2012).

– See more at: Rice News

Flat boron by the numbers

Rice University researchers calculate what it would take to make new two-dimensional material

It would be a terrible thing if laboratories striving to grow graphene from carbon atoms kept winding up with big pesky diamonds.

“That would be trouble, cleaning out the diamonds so you could do some real work,” said Rice University theoretical physicist Boris Yakobson, chuckling at the absurd image.

Yet something like that keeps happening to experimentalists working to grow two-dimensional boron. Boron atoms have a strong preference to clump into three-dimensional shapes rather than assemble into pristine single-atom sheets, like carbon does when it becomes graphene. And boron clumps aren’t nearly as sparkly…more

Flat boron may take many forms

When is nothing really something? When it leads to a revelation about boron, an element with worlds of unexplored potential.

Theoretical physicist Boris Yakobson and his team at Rice University have taken an unusual approach to analyzing the possible configurations of two-dimensional sheets of boron, as reported this week in the American Chemical Society journal Nano Letters. more…