摘要：Ilmenite, FeTiO3, is a common mineral in nature, existing as an accessory phase in the most basic igneous and metamorphic rocks, for example, it is derived from the upper mantle. Therefore, an understanding of the high-pressure physics of FeTiO3 is of fundamental importance in the study of rock magnetization. Here, we provide experimental evidence of lattice compression of FeTiO3 powder using super-high-energy ball milling, enabling the very high collision energy of 420 times gravitational acceleration. A sample obtained as an ilmenite- hematite 0.5FeTiO3·0.5Fe2O3 solid solution showed a decrease in molar volume of approximately 1.8%. Consequently, the oxidation state in FeTiO3 powder was changed into almost Fe3 Ti3 , corresponding to 87% Fe3 of the total Fe for FeTiO3, resulting in the emergence of ferromagnetism. This new ferromagnetic behaviour is of crucial importance in the study of rock magnetization which is used to interpret historical fluctuations in geomagnetism. In addition, the super-high-energy ball mill can be used to control a range of charge and spin states in transition metal oxides with high pressure.
