Journal of Experimental and Theoretical Physics Letters · 2003 · 29 citations · 8 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsOptical MaterialsSolid State PhysicsIron OxidesMagnetic OxidesMagnetic Properties Of SolidsMagnetism In SolidsOptical Properties Of SolidsPhase TransitionsHigh-pressure Phase BehaviorHigh-pressure Phase TransitionsHigh-pressure Transport PropertiesOptical PropertiesSurface Optical Properties
The optical absorption spectra of iron borate FeBO 3 were measured in diamond anvil cells at high pressures up to P =82 GPa. The electronic transition with an abrupt jump in the absorption edge from ∼3 to 0.8 eV was observed at P ≈46 GPa. The resistance and its temperature dependence were directly measured for FeBO 3 at high pressures up to 140 GPa. It was established that the electronic transition at P ≈46 GPa was accompanied by the insulator-semiconductor transition. In the high-pressure phase, the thermoactivation gap decreases smoothly at 46< P <140 GPa approximately from 0.55 to 0.2 eV following the linear law. The extrapolated value of the pressure at which the sample becomes fully metallic is equal to about 210 GPa.
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