D. L. Windt, W. C. Cash, M. Scott, P. Arendt, B. Newnam, R. F. Fisher, A. B. Swartzlander. Optical constants for thin films of Ti, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Ir, Os, Pt, and Au from 24 Å to 1216 Å, Appl. Opt.27, 246-278 (1988)
Rhenium (Re) is a silvery-white, heavy transition metal with an atomic number of 75 in the periodic table. It is found in small amounts in certain minerals like columbite and molybdenite, from which commercial rhenium is extracted as a by-product of molybdenum refinement. With one of the highest melting points among all elements, rhenium retains its strength at high temperatures, making it valuable for applications in jet engines and other high-temperature environments. Its alloys, especially with molybdenum, have excellent resistance to wear and can withstand extreme temperatures without softening. Rhenium is also used as a catalyst in certain chemical reactions, notably in the production of high-octane gasoline. Additionally, it finds applications in electrical contacts and filaments due to its high melting point and good wear resistance.