A team of researchers at Ehime University Geodynamics Research Center (GRC) led by ELSI Prof. Tetsuo Irifune, director of GRC, succeeded in determining the melting temperature of Periclase (MgO) under ultra-high pressure based on new experimental technology using Co2 laser. As a result, they found that MgO has the highest melting temperature (5,600℃ at 50 GPa) among minerals that consist of mantle. The result shed light on the chemical composition of the deepest mantle which is still unknown.
For more details, please see Ehime University's website and the press release document. (sorry only Japanese press release is available)
Title：Melting temperatures of MgO under high pressure by micor-texture analysis
Tomoaki Kimura, Hiroaki Ohfuji, Nishi Masayuki, Tetsuo Irifune
Ehime University Geodynamics Research Center