what material makes up the inner core

The inner core of the Earth is believed to be composed mainly of iron and nickel in an alloy represented with the chemical formula NiFe. The inner core is under intense pressure, which keeps it solid despite high temperatures. The temperature at the inner cores surface is estimated to be about 5,200° Celsius (9,392° Fahrenheit) . Although there is no direct evidence about the composition of the inner core, based on the relative prevalence of various chemical elements in the Solar System, the theory of planetary formation, and constraints imposed or implied by the chemistry of the rest of the Earths volume, the inner core is believed to consist primarily of an iron–nickel alloy.