Which layer of the Earth is believed to be formed of molten iron and nickel?
Allotropes of iron the solid parts of planetary cores. The inner core of the Earth is generally assumed to consist essentially of a crystalline iron-nickel alloy with ε structure. The outer core surrounding the solid inner core is believed to be composed of liquid iron mixed with nickel and trace amounts of lighter elements. As molten iron cools down, it solidifies at 1,538 °C (2,800 °F) into its δ allotrope, which has a body-centered cubic (BCC) crystal structure. δ-iron can dissolve as much as 0.08% of carbon by mass at 1,475 °C. As the iron cools further to 1,394 °C its crystal structure
Iron–nickel alloy elements formed with a supernova or similarly cataclysmic event. Iron and nickel are the most abundant metals in metallic meteorites and in the dense metal cores of planets such as Earth. Nickel–iron alloys occur naturally on Earth's surface as telluric or meteoric iron. The affinity of nickel atoms (atomic number 28) for iron (atomic number 26) results in natural occurring alloys and a large number of commercial alloys, and provides a complex electron environment for catalyzing chemical reactions. In steel metallurgy, nickel is alloyed with iron to produce maraging steel and some low-alloy steels. Other technological uses include Invar and