Photoluminescence critical behavior in Er3+ doped Ba0.77Ca0.23TiO3 ceramic

We developed a non-contact and non-destructive method to detect Curie point (TC) in Er3+ doped Ba0.77Ca0.23TiO3 (BCT) ferroelectric ceramic. Through investigating the photoluminescence (PL) spectra of Er3+ doped BCT ceramic we found that PL characteristics in ferroelectrics demonstrates critical behavior around TC. Both intensity and peak positions of the Stark sub-peaks originating from 4S3/2 to 4I15/2 transition change dramatically, and can be fitted with two different lines below and above TC. The inflection points of the PL characteristics are at the same temperature of 381(1) K, and coincident with the TC (381 K) determined by the dielectric temperature spectrum.