Table of Contents Author Guidelines Submit a Manuscript
Journal of Nanomaterials
Volume 2017, Article ID 3108586, 9 pages
https://doi.org/10.1155/2017/3108586
Research Article

Physical Background for Luminescence Thermometry Sensors Based on Pr3+:LaF3 Crystalline Particles

1Kazan Federal University, Kazan, Tatarstan 420008, Russia
2Kazan National Research Technological University, Kazan, Tatarstan 420015, Russia

Correspondence should be addressed to Maksim S. Pudovkin; ur.tsil@8777zaj

Received 12 May 2017; Revised 31 July 2017; Accepted 15 August 2017; Published 24 September 2017

Academic Editor: Victor M. Castaño

Copyright © 2017 Maksim S. Pudovkin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The main goal of this study was creating multifunctional nanoparticles based on rare-earth doped LaF3 nanocrystals, which can be used as fluorescence thermal sensors operating over the 80–320 K temperature range including physiological temperature range (10–50°C). The Pr3+:LaF3 ( = 1%) microcrystalline powder and the Pr3+:LaF3 ( = 12%, 20%) nanoparticles were studied. It was proved that all the samples were capable of thermal sensing into the temperature range from 80 to 320 K. It was revealed that the mechanisms of temperature sensitivity for the microcrystalline powder and the nanoparticles are different. In the powder, the 3P1 and 3P0 states of Pr3+ ion share their electronic populations according to the Boltzmann and thermalization of the 3P1 state takes place. In the nanoparticles, two temperature dependent mechanisms were suggested: energy migration within 3P0 state in the temperature range from 80 K to 200 K followed by quenching of 3P0 state by OH groups at higher temperatures. The values of the relative sensitivities for the Pr3+:LaF3 ( = 1%) microcrystalline powder and the Pr3+:LaF3 ( = 12%, 20%) nanoparticles into the physiological temperature range (at 45°C) were 1, 0.5, and 0.3% °C−1, respectively.