All articles tagged with #thermal expansion
NASA-funded research has developed a new alloy with negative thermal expansion properties that can significantly improve the stability of space telescope structures, enabling more precise detection of habitable exoplanets by maintaining ultra-stable optical systems necessary for future missions like the Habitable Worlds Observatory.
Researchers have generated high-density, spontaneous magnetic biskyrmions in a rare earth magnet without the need for an external magnetic field. By studying the negative thermal expansion of a lattice in a holmium-cobalt compound, the team observed the formation of stable biskyrmions across a wide temperature range. This discovery could have significant implications for the development of spintronic storage devices and other applications in the field of magnetism.
Scientists have finally discovered why certain alloys, such as Invar, do not expand when heated. These alloys, which contain specific ratios of iron and other metals like nickel, exhibit an exception to the general rule that materials expand when heated. The researchers found that magnetism plays a crucial role in balancing out the entropy caused by heat, preventing the atoms in the alloy from moving further apart. This understanding could have applications in precise instrument manufacturing and infrastructure building, where heat-sensitive metals can cause problems. The study improves our understanding of thermal expansion in other magnetizable materials.
Researchers from the California Institute of Technology have discovered the secret behind the unusual behavior of Invar alloys, which do not change in size and density over a wide range of temperatures. By measuring the vibrational spectra and magnetism of Invar samples, the researchers found a delicate balance between thermal expansion caused by atom vibrations and magnetism. The interaction between vibrations and magnetism, such as altered frequencies of atom vibrations, helps maintain this balance. This finding could aid in understanding thermal expansion in other magnetic materials and developing materials for magnetic refrigeration.
Researchers have discovered the secret behind the unusual behavior of a class of metal alloys called Invars, which do not change in size and density over a wide range of temperatures. By combining iron and nickel in a specific proportion, these alloys exhibit a counteracting effect between thermal expansion caused by atom vibrations and magnetism. The spin state of electrons in the Invar alloys changes with temperature, causing the atoms to vibrate more and take up more space, while the changing spin states also lead to contraction. This delicate balance explains why Invars remain the same size. The findings could have implications for understanding thermal expansion in other magnetic materials and developing materials for magnetic refrigeration.