Barium ferrite these species include BaFeO, BaFeO, and BaFeO. A one-step hydrothermal process can be used to form crystals of barium ferrite, by mixing barium chloride, ferrous chloride, potassium nitrate, and sodium hydroxide with a hydroxide to chloride concentration ratio of 2:1. Nanoparticles are prepared from ferric nitrate, barium chloride, sodium citrate, and sodium hydroxide. The typical preparation, however, is by calcining barium carbonate with iron(III) oxide: Barium ferrite has been considered for long term data storage. The material has proven to be resistant to a number of different environmental stresses, including humidity and corrosion. Because ferrites are already oxidized it can
Chemical element element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust. Chemical elements constitute all of the ordinary matter of the universe. However astronomical observations suggest that ordinary observable matter makes up only about 15% of the matter in the universe: the remainder is dark matter; the composition of this is unknown, but it is not composed of chemical elements. The two lightest elements, hydrogen and helium, were mostly formed in the Big Bang and are the most common elements in the universe. The next three elements (lithium, beryllium and boron) were formed mostly