Effect of temperature on the formation of luminescent nanostructures in KBr:Eu2+

Abstract

 The study of the effect of temperature on the formation of luminescent nanostructures (NsL) in the single crystal of KBr:Eu²⁺ is presented. The samples were stored for 16 weeks at 100 and 200 °C to form the Suzuki phase (FS) and dihalide phase (FD), respectively, the concentration of impurities in both cases was ~380 ppm. The formation of nanostructures was studied by optical spectroscopy (OE) and the images were obtained by atomic force microscopy (AFM). The absorption and emission spectra report important changes in 10 Dq for the FS at 11365.2 cm^–1, with a mission peak at 433 nm, and for the FD 10 Dq at 5319.3 cm^–1 with two characteristic emission peaks at 428.5 and 450.7 nm of the dihalide phase. The images observed by AFM show that the NsL for the FS range from 40 to 435 nm in diameter with heights of 9 to 120 nm, in contrast to the FD where there is a dispersion of sizes is from 20 nm to 500 nm in diameter, but with limited heights in the range 1 to 7 nm. These results prove theoretical suppositions that indeed the DF is of the laminar type, the results obtained are in agreement with the literature data.