#strain engineering

Room-temperature multiferroic could pave way to low-energy computing

A team of researchers at Rice University has engineered a new version of a well-known multiferroic that exhibits orders of magnitude higher performance at room temperature than its parent material. The study, published in the Proceedings of the National Academy of Sciences, describes a modified version of bismuth ferrite that shows a 10-fold increase in magnetization and 100-fold increase in magnetoelectric coupling compared to standard varieties. The synthesis process entailed mixing bismuth ferrite with barium titanate while simultaneously growing the material as a thin film on a substrate that distorts its crystal structure.

A 1950s material just set a modern record for lightning-fast chips

Record-breaking germanium-on-silicon tech promises faster, cooler, next-gen electronics and quantum devices.

Scientists from the University of Warwick and the National Research Council of Canada have reported the highest "hole mobility" ever measured in a material that works within today's silicon-based semiconductor manufacturing. Silicon (Si) forms the foundation of most modern semiconductor devices, but as components shrink and are packed closer together, they generate more heat and approach fundamental performance limits. Germanium (Ge), which appeared in some of the earliest transistors of the 1950s, is drawing renewed interest because researchers are finding ways to take advantage of its superior electrical characteristics while retaining the benefits of established silicon production methods.

A mechanical blue LED: Stretching GaN shifts light from UV to blue without changing chemistry

A research team from the Faculty of Engineering at the University of Hong Kong (HKU) has successfully used mechanical stretching technology to dynamically control the emission color of gallium nitride (GaN) material from ultraviolet (UV) to blue light. This technological breakthrough provides a new semiconductor material control solution for future advanced power transistors, optoelectronic components, radio frequency components, and micro-LED displays. The findings have been published in Physical Review X in a paper titled "Deep Elastic Strain Engineering of Free-Standing GaN Microbridge." Led by Professor Yang Lu from the Department of Mechanical Engineering, the team utilized micro-nano processing technology to fabricate single-crystalline GaN material into tiny bridge-like structures.

Super strain-resistant superconductors: Study narrows down the hidden symmetry

Superconductors are materials that can conduct electricity with zero resistance, usually only at very low temperatures. Most superconductors behave according to well-established rules, but strontium ruthenate, Sr₂RuO₄, has defied clear understanding since its superconducting properties were discovered in 1994. It is considered one of the cleanest and best-studied unconventional superconductors, yet scientists still debate the precise structure and symmetry of the electron pairing that gives rise to its remarkable properties. How strain reveals superconducting states One powerful way to identify the underlying superconducting state is to measure how the superconducting transition temperature, or Tc, changes under strain, since different superconducting states respond differently when a crystal is stretched, compressed, or twisted.

Elastic strain engineering boosts green hydrogen production with affordable catalysts

Researchers from IMDEA Materials Institute have demonstrated improved and more affordable catalytic materials used to produce green hydrogen. In a study published in ACS Catalysis, intermetallic thin films made from three low-cost alloys: silver and indium (Ag₃In), nickel and iron (Ni₃Fe) and nickel and tin (Ni₃Sn), showed significant gains in catalytic efficiency for the hydrogen evolution reaction (HER) when subjected to controlled elastic strains. The findings point to elastic strain engineering as a promising avenue to develop affordable catalysts that could replace platinum-group metals in industrial hydrogen production.

Lead-free alternative discovered for essential electronics component

Ferroelectric materials are used in infrared cameras, medical ultrasounds, computer memory and actuators that turn electric properties into mechanical properties and vice-versa. Most of these essential materials, however, contain lead and can therefore be toxic. "For the last 10 years, there has been a huge initiative all over the world to find ferroelectric materials that do not contain lead," said Laurent Bellaiche, Distinguished Professor of physics at the University of Arkansas. The atoms in a ferroelectric material can have more than one crystalline structure. Where two crystalline structures meet is called a phase boundary, and the properties that make ferroelectric materials useful are strongest at these boundaries.

Strained strontium titanate membrane crosses into ferroelectric—and quantum—territory

Strontium titanate was once used as a diamond substitute in jewelry before less fragile alternatives emerged in the 1970s. Now, researchers have explored some of its more unusual properties, which might someday be useful in quantum materials and microelectronics applications. Writing in the journal Nature Communications, the team explains how they built an extremely thin, flexible strontium titanate membrane and stretched it, in the process turning on what's known as a ferroelectric state. In that state, the material generates its own electric field, somewhat similar to how a permanent magnet generates its own magnetic field. "We applied strain to tune the membrane to a ferroelectric or non-ferroelectric state reversibly and repeatedly," said Wei-Sheng Lee, a lead scientist at the Department of Energy's SLAC National Accelerator Laboratory and a principal investigator at the Stanford Institute for Materials and Energy Sciences (SIMES), a joint SLAC-Stanford institute. "This allowed quantitative characterizations of this transition in strontium titanate with unprecedented details."

Research illuminates the path to superior electro-optic performance in aluminum scandium nitride alloys

From integrated photonics to quantum information science, the ability to control light with electric fields—a phenomenon known as the electro-optic effect—supports vital applications such as light modulation and frequency transduction. These components rely on nonlinear optical materials, in which light waves can be manipulated by applying electric fields. Conventional nonlinear optical materials such as lithium niobate have a large electro-optic response but are hard to integrate with silicon devices. In the search for silicon-compatible materials, aluminum scandium nitride (AlScN), which had already been flagged as an excellent piezoelectric—referring to a material's ability to generate electricity when pressure is applied, or to deform when an electric field is applied—has come to the fore. However, better control of its properties and means to enhance its electro-optic coefficients are still required.