Advantages and innovations of NIMS

Light-emitting diodes (LEDs) are very energy-efficient lighting devices. Early white LED bulbs were able to generate white light when their blue LED chips were coated with a yellow phosphor.

However, their blue-tinged white light made them unpopular for use in lighting fixtures. A red phosphor was needed to generate natural white light, but it had yet to be invented. NIMS tackled this challenge and succeeded in developing a red sialon phosphor, enabling LEDs to emit natural white light. Today, these white LEDs are commonly used in lighting fixtures around the world. The sialon phosphors NIMS developed revolutionized lighting technologies and have become a global standard.

When the Great East Japan Earthquake occurred, long-period ground motion was widely reported by media outlets as far from the epicenter as Osaka, causing skyscrapers to sway for long periods of time. To prevent damage caused by this phenomenon, many new buildings are equipped with seismic dampers. However, once a building experiences a massive earthquake, the performance of its dampers degrades, requiring them to be replaced through large-scale civil engineering work.

NIMS has developed a shape-memory FMS alloy highly resistant to the fatigue caused by repeated deformation. In addition to its ability to absorb external stress, the fatigue strength of this alloy is 10 times higher than that of conventional damper materials. Because of these advantages, the alloy has been integrated into the seismic dampers used in some buildings, which require no maintenance or replacement. This is an example of NIMS’ efforts to protect buildings from major earthquakes.

Data centers established around the world store huge amounts of digital information primarily using hard disk drives (HDDs). According to one estimate, these data centers will account for 10% of total global power consumption within a decade. More energy-efficient, higher density data storage technologies are therefore needed. NIMS succeeded in developing the world’s first HAMR (heat-assisted magnetic recording) media—a ultrahigh-density recording technology—using a new FePt material. HAMR HDDs are already in practical use, supporting our advanced information society.

The 1988 discovery of a bismuth-based high-temperature superconducting material by the National Research Institute for Metals (a predecessor of NIMS) surprised the global scientific community.

The electrical resistance of superconducting materials abruptly drops to zero when they are cooled to their critical temperatures. In 1986, Swiss and German scientists jointly discovered a material capable of superconductivity at 35 K (-238°C)—a temperature significantly higher than previously known critical temperatures. They won the Nobel Prize in Physics for this discovery. Although a number of different high-temperature superconductors have since been discovered, the bismuth-based superconductor NIMS developed is different from them in chemical composition and has a very high critical temperature of over 100 K (-173°C), suggesting that superconductivity could occur at temperatures higher than previously reported.

This bismuth-based superconducting material may potentially be used to develop resistance-free power transmission cables and very strong electromagnets, and testing is underway to put it into practical use.