Publication: Investigation of optical and dielectric properties of Dy3+ doped tellurite-based glass systems
Abstract
TeO2-TiO2-ZnO-WO3-Dy2O3 ve TeO2-TiO2-ZnO-Nb2O5-Dy2O3 camları eriyik söndürme yöntemine göre sentezlenmiştir. Sentezlenen camların optik ve dilektrik özellikleri Dy+3 iyon konsantrastyonuna bağlı olarak incelenmiştir. Mott-Davis ilişkisi kullanılarak camların optik band aralıkları hesaplanmıştır. İncelenen camlarda Dy+3 iyon konsantrasyonu arttıkça band aralıkları azalmıştır. Ayrıca her iki cam sisteminde de Dy+3 konsantrasyonu arttığında Urbach enerjisi de azalmıştır. Camların hesaplanan yoğunlukları ve lineer kırılma indisleri her iki cam sistemi içinde artan Dy+3 konsantrasyonu ile artmıştır. Camların soğurma spektrumları 300 nm ile 2000 nm aralığında alınmış ve Dy+3 iyonlarının beş adet soğurma bandı gözlenmiştir. Bu bantlar arasında 6H15/ 2→6H9/ 2+6F11/ 2 (1280 nm) geçişi ile gözlenen şiddetli soğurma bandı aşırı duyarlı geçiş bandı olarak bilinir. Camların Judd-Ofelt parametreleri geleneksel en küçük kareler yöntemi kullanılarak hesaplanmıştır. Hazırlanan camlardan TTZWD1 ve TTZND1 hariç diğerleri Ω2 > Ω4 >Ω6 eğilimine sahip olacak şekilde bir davranış göstermiştir. Judd-Ofelt parametresi Ω2’nin değeri 70TeO2-5TiO2-15ZnO-(10-x) WO3'te camında Dy+3 iyon konsanatrasyonu ile artarken, 70TeO2-5TiO2-15ZnO-(10-x)Nb2O5 camında azalmıştır. Camların dielektrik özellikleri bir empedans analizörü kullanılarak 100Hz - 1 MHz aralığında frekans aralığında incelenmiştir. İncelenen camlarda dielektrik sabiti Dy+3 iyon konsantrasyonuna bağlı olarak önemli bir ölçüde değişiklik göstermiştir.
Optical and dielectric properties of 70TeO2-5TiO2-15ZnO-(10-x)Nb2O5-xDy2O3 and 70TeO2-5TiO2-15ZnO-(10-x)WO3-xDy2O3 glasses were investigated. Direct/ Indirect allowed/ forbidden bandgaps calculated using Mott-Davis formula. All of them decreased when Dy3+ concentration increase in the studied glasses. Urbach energy decreased when Dy3+ concentration increases in both of the studied glass systems. Density and linear refractive index were also calculated. They increased when Dy increased in both of the glass systems. The absorption spectrum of Dy3+ dopped glasses in the range 300nm to 2000nm was taken and it showed five absorption peaks. The 6H15/ 2→6H9/ 2+6F11/ 2 (1280 nm) transition is considered as a hypersensitive transition for Dy3+ ions in both of the glass systems. Judd-Ofelt parameters were calculated using the conventional least-squares method. All of them showed a similar trend Ω2>Ω4 >Ω6 except for TTZWD1 and TTZND1. The value of the first Judd-Ofelt parameter Ω2 increased with the increase of Dy3+ in 70TeO2-5TiO2-15ZnO-(10-x)WO3 while it decreased with the increase of Dy concentration in 70TeO2-5TiO2-15ZnO-(10-x)Nb2O5 glass system. The dielectric properties of these glasses were studied using an impedance analyzer. The variation of the dielectric constant with frequency in the 100-1MHz range did show any significant change in the studied glasses. However, it changed significantly with the addition of Dy3+.
Optical and dielectric properties of 70TeO2-5TiO2-15ZnO-(10-x)Nb2O5-xDy2O3 and 70TeO2-5TiO2-15ZnO-(10-x)WO3-xDy2O3 glasses were investigated. Direct/ Indirect allowed/ forbidden bandgaps calculated using Mott-Davis formula. All of them decreased when Dy3+ concentration increase in the studied glasses. Urbach energy decreased when Dy3+ concentration increases in both of the studied glass systems. Density and linear refractive index were also calculated. They increased when Dy increased in both of the glass systems. The absorption spectrum of Dy3+ dopped glasses in the range 300nm to 2000nm was taken and it showed five absorption peaks. The 6H15/ 2→6H9/ 2+6F11/ 2 (1280 nm) transition is considered as a hypersensitive transition for Dy3+ ions in both of the glass systems. Judd-Ofelt parameters were calculated using the conventional least-squares method. All of them showed a similar trend Ω2>Ω4 >Ω6 except for TTZWD1 and TTZND1. The value of the first Judd-Ofelt parameter Ω2 increased with the increase of Dy3+ in 70TeO2-5TiO2-15ZnO-(10-x)WO3 while it decreased with the increase of Dy concentration in 70TeO2-5TiO2-15ZnO-(10-x)Nb2O5 glass system. The dielectric properties of these glasses were studied using an impedance analyzer. The variation of the dielectric constant with frequency in the 100-1MHz range did show any significant change in the studied glasses. However, it changed significantly with the addition of Dy3+.