Osmium is Stiffer than Diamond, Scientists Discover

Whether it will compete for the title of a girl’s best friend remains to be seen but the element osmium can already challenge diamond in at least one respect: stiffness. According to a report published in the current issue of Physical Review Letters, osmium can withstand compression better than any known material. The results provide a potentially new lead in the search for superhard materials.

Diamond’s ability to resist scratches, dents and chipping–in short, its hardness–makes it an ideal choice for tips in industrial strength machines. A related quality that is easier to calculate than hardness is an element’s resistance to compression, as known as its bulk modulus. The properties are interrelated because the stiffest materials also tend to be the hardest ones. But even though osmium is much softer than diamond, initial estimates of its bulk modulus indicated a similar value to that of diamond.

Hyunchae Cynn and colleagues at Lawrence Livermore National Laboratory thus set out to test the property experimentally. They squeezed osmium powder under 600,000 atmospheres of pressure and calculated changes in the spacing between atoms in the sample using x-ray diffraction patterns. The team reports that osmium’s bulk modulus is 462 gigapascals (GPa) as compared to diamond’s 443 GPa. “It is intriguing that a light, covalently bonded element such as diamond and a heavy, metallic element such as osmium, with very different chemical bonding, would both have large values of the bulk modulus,” the authors note. They conclude that related compounds such as transition metal carbides, nitrides and oxides could be sources of new superhard materials. —

Media Contact

Sarah Graham News in Brief

All latest news from the category: Materials Sciences

Materials management deals with the research, development, manufacturing and processing of raw and industrial materials. Key aspects here are biological and medical issues, which play an increasingly important role in this field.

innovations-report offers in-depth articles related to the development and application of materials and the structure and properties of new materials.

Back to home

Comments (0)

Write a comment

Newest articles

When the music changes, so does the dance

Controlling cooperative electronic states in Kagome metals. Playing a different sound track is, physically speaking, only a minute change of the vibration spectrum, yet its impact on a dance floor…

EcoFABs could lead to better bioenergy crops

Fabricated ecosystems created at Berkeley Lab will expedite microbiome research, and help underrepresented students in the classroom. A greater understanding of how plants and microbes work together to store vast…

Rice lab finds better way to handle hard-to-recycle material

Process transforms glass fiber-reinforced plastic into silicon carbide. Glass fiber-reinforced plastic (GFRP), a strong and durable composite material, is widely used in everything from aircraft parts to windmill blades. Yet…

Partners & Sponsors