AUTHOR=Elzbieciak Karolina , Marciniak Lukasz 

TITLE=The Impact of Cr3+ Doping on Temperature Sensitivity Modulation in Cr3+ Doped and Cr3+, Nd3+ Co-doped Y3Al5O12, Y3Al2Ga3O12, and Y3Ga5O12 Nanothermometers

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 6 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00424

DOI=10.3389/fchem.2018.00424

ISSN=2296-2646

ABSTRACT=A new approach to enhance the sensitivity of transition metal ion based nanocrystalline luminescent thermometer is presented. It was shown that the increase of Cr3+ concentration in three types of garnet host namely Y3Al5O12, Y3Ga5O12 and Y3Al2Ga3O12 allows for significant enhancement of their performance in non-contact thermometry. This phenomenon is related to the weakening of the crystal field strength due to enlargement of average Cr3+-O2- distance at higher Cr3+ concentrations. By increasing Cr3+ concentration from 0.6% to 30%, the  sensitivity increased by over one order of magnitude from S=0.2%/oC to S=2.2%/oC at 9oC in Y3Al2Ga3O12 nanocrystals. Moreover, it was found that due to the Cr3+→Nd3+ energy transfer in the Cr3+, Nd3+ co-doped system, the usable Cr3+ concentration, for which its emission can be detected, is limited to 10% while the sensitivity at -50 oC  was doubled (from 1.3%/oC for Y3Al2Ga3O12:10%Cr3+ to 2.2%/oC Y3Al2Ga3O12:10%Cr3+, 1%Nd3+ nanocrystals).