报告题目：High pressure luminescence and Raman studies of Eu2+and Mn2+doped NaScSi2O6jervisite
Clinopyroxenes of general chemical formula NaMe3+Si2O6are members of big family of pyroxenes compounds, which are components of many rocks. They are stable in over a wide range of pressures and temperatures, which makes them also interesting as functional materials. Upon doping with Eu and Eu/Mn they exhibit interesting properties for application as phosphors for white-light-emitting diodes.
High-pressure luminescence studies of NaScSi2O6jervisite powders doped with Eu2+(5%), Mn2+(5%), and Eu2+(5%)/Mn2+(15%), prepared by sol-gel method, were performed in diamond anvil cells with pressures up to 32 GPa and various temperatures from 5 K up to 500 K. Luminescence spectra and luminescence decay kinetics of both Eu2+and Mn2+were studied.
Temperature dependence of luminescence spectra of doubly doped sample at ambient pressure exhibit quenching of Eu emission, which occurs at lower temperatures than quenching of Mn luminescence.
High pressure experiments shows that luminescence bands associated with Eu2+and Mn2+exhibit red shifts with increase of pressure, however with various pressure coefficients, equal to approximately -6 cm-1/GPa and -15 cm-1/GPa for Eu2+and Mn2+, respectively. The shifts can be well explained by the influence of the increased crystal field strength with increased pressure. Pressure-induced weak incr
ease of efficiency of the energy transfer efficiency from Eu2+to Mn2+ions is observed at room temperature. However there is no temperature influence the efficiency of the energy transfer between thes