That’s really interesting
That’s really interesting
Most metals expand when heated, but materials like Invar resist this due to changes in magnetic order. Researchers at TU Wien and UST Beijing used simulations to understand this effect, leading to the development of a pyrochlore magnet with even better thermal stability over a wide temperature range. Credit: TU Wien Scientists have developed a new alloy composed of multiple metals that exhibits nearly zero thermal expansion across an exceptionally wide temperature range.
Most metals expand as their temperature rises. The Eiffel Tower, for example, stands about 10 to 15 centimeters taller in summer than in winter due to thermal expansion. However, this effect is highly undesirable for many technical applications. As a result, researchers have long sought materials that maintain a constant length regardless of temperature. One such material is Invar, an iron-nickel alloy known for its extremely low thermal expansion. The physical explanation for this property, however, remained unclear until recently.
Now, a collaboration between theoretical researchers at the Vienna University of Technology (TU Wien) and experimentalists at the University of Science and Technology Beijing has led to a significant breakthrough. Using complex computer simulations, they have unraveled the invar effect in detail and developed a so-called pyrochlore magnet—an alloy with even better thermal expansion properties than Invar. Over an exceptionally wide temperature range of more than 400 Kelvins, its length changes by only about one ten-thousandth of one percent per Kelvin.
Thermal expansion and its antagonist “The higher the temperature in a material, the more the atoms tend to move – and when the atoms move more, they need more space. The average distance between them increases,” explains Dr Sergii Khmelevskyi from the Vienna Scientific Cluster (VSC) Research Centre at TU Wien. “This effect is the basis of thermal expansion and cannot be prevented. But it is possible to produce materials in which it is almost exactly balanced out by another, compensating effect.” . .
>Most metals expand when heated, but materials like Invar resist this due to changes in magnetic order. Researchers at TU Wien and UST Beijing used simulations to understand this effect, leading to the development of a pyrochlore magnet with even better thermal stability over a wide temperature range. Credit: TU Wien
Scientists have developed a new alloy composed of multiple metals that exhibits nearly zero thermal expansion across an exceptionally wide temperature range.
>Most metals expand as their temperature rises. The Eiffel Tower, for example, stands about 10 to 15 centimeters taller in summer than in winter due to thermal expansion. However, this effect is highly undesirable for many technical applications. As a result, researchers have long sought materials that maintain a constant length regardless of temperature. One such material is Invar, an iron-nickel alloy known for its extremely low thermal expansion. The physical explanation for this property, however, remained unclear until recently.
>Now, a collaboration between theoretical researchers at the Vienna University of Technology (TU Wien) and experimentalists at the University of Science and Technology Beijing has led to a significant breakthrough. Using complex computer simulations, they have unraveled the invar effect in detail and developed a so-called pyrochlore magnet—an alloy with even better thermal expansion properties than Invar. Over an exceptionally wide temperature range of more than 400 Kelvins, its length changes by only about one ten-thousandth of one percent per Kelvin.
>Thermal expansion and its antagonist
“The higher the temperature in a material, the more the atoms tend to move – and when the atoms move more, they need more space. The average distance between them increases,” explains Dr Sergii Khmelevskyi from the Vienna Scientific Cluster (VSC) Research Centre at TU Wien. “This effect is the basis of thermal expansion and cannot be prevented. But it is possible to produce materials in which it is almost exactly balanced out by another, compensating effect.”
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