Abstract
This work presents a time-resolved spectroscopic study of MnF2 as grown and milled into nanoparticles. We find that high pressure (HP) induces photoluminescence (PL) at room temperature (RT) above 13 GPa in MnF2 single crystals. RT-PL occurs as a consequence of the inhibition of excitation migration processes among Mn2+ ions resulting from the HP-induced structural phase transition (SPT) to the α-PbCl2-type phase. This SPT involves important changes in the Mn– F– Mn exchange paths yielding radiative de-excitation in Mn2+, and thus also PL. As a salient result, we have found an increase of the PL-quenching temperature in nanosized milled MnF2.
Acknowledgements
Financial support from the Spanish MEC (Project No. MAT2005-00099) is acknowledged. Dr. Hernández thanks the Research Intensification Program I3 of the University of Cantabria for a research contract.