Akademik Veri Yönetim Sistemi
SPECTROSCOPY LETTERS, cilt.47, sa.10, ss.746-753, 2014 (SCI-Expanded)
The three-dimensional photoluminescence emissions between 450 and 800nm of kammererite from Turkey were obtained at the temperatures between 230 and 350K under 366nm excitation. The most advantage of three-dimensional photoluminescence is to demonstrate clearly all vibronic structures through temperature increasing on the spectra. Hence, photoluminescence response from the unique gem material was discussed in relation to chemical impurities. In the photoluminescence spectra, two strong and three weaker emission bands became clear at the lower temperature conditions. First strong green band with the highest emission peak at 545nm, and second strong yellowish-orange band with the highest emission peak at 610nm were observed at 230K. The half-width of the main bands is approximately 10-12nm and such band's combination is typical for trivalent rare-earth elements. These two strong emission bands are due to europium and gadolinium ions, respectively. In addition, the weaker emission bands at 485, 585, and 615nm were detected at mainly 230K. The bands peaked at 485 was attributed to lanthanum, lutetium, promethium, scandium, and yttrium centers, and 585nm was attributed to dysprosium center. Since, the abundances of these rare-earth elements produced relatively strong luminescence bands in the spectra. Finally, the weakest band peaked at 615nm was attributed to neodymium. As a result, the intensities of these bands gradually decreased forming a sequence until the temperature of 280K. The lanthanum is the main responsible ion that extinguishes the photoluminescence at the relatively higher temperature conditions in the minerals. Therefore, the photoluminescence of kammererite exists at low temperatures only, because of mainly high lanthanum (90ppm) abundance.