LOW TEMPERATURE SOLID-STATE SYNTHESIS AND CHARACTERIZATION OF LaBO3

Nadir toprak (Lantanit serisi) boratları, yüksek vakum ultraviyole şeffaflığına, büyük elektronik bant boşluğuna, kimyasal ve çevresel güvenilirliğe ve son derece geniş optik hasar eşiğine sahiptir. Bu özelliklerinden dolayı plazma ekran panellerinin geliştirilmesinde kullanılmaktadır. Bu çalışmada, katıhal yöntemi ile lantan borat üretimi çalışılmıştır. Bu amaçla, lantan oksit (La2O3) ve borik asit (H3BO3) sırası ile lantan ve bor kaynağı olarak kullanılmıştır. Farklı elementel La ve B oranları (La2O3:H3BO3olarak 3:1 den 1:6 ya kadar) katı-hal yöntemi ile 500°C - 700°C reaksiyon sıcaklıklarında, 4 saat süre ile reaksiyona sokulmuşlardır. Sentez sonrası ürünlerin karakterizasyonu X-ışınları difraktometresi (XRD), Fourier dönüşümlü kızıl ötesi spektroskopisi (FT-IR), Raman spektroskopisi ve taramalı electron mikroskobu (SEM) teknikleri ile gerçekleştirilmiştir. Deney sonuçlardan görüldüğü üzere, La3BO6, LaBO3 ve La(BO2)3 yapısında üç farklı lantan borat bileşiği farklı parameterlerde saptanmıştır. Elde edilen farklı lantan borat bileşiklerinden LaBO3 bileşiği major faz olarak elde edilmiştir

Katı-Hal Yöntemi ile Düşük Sıcaklıklarda LaBO3üretimi ve Karakterizasyonu

Rare earth (lanthanide series) borates, possess high vacuum ultraviolet (VUV) transparency, large electronic band gaps, chemical and environmental stability and exceptionally large optical damage thresholds. For this properties, they are used in the development of plasma display panels (PDPs). In this study the synthesis of lanthanum borates via solid-state method is studied. For this purpose, lanthanum oxide (LaO3) and boric acid (H3BO3) are used for as lanthanum and boron sources, respectively. Different elemental molar ratios of La to B (between 3:1 to 1:6 as La2O3:H3BO3) were reacted by solidstate method at the reaction temperatures between 500°C - 700°C with the constant reaction time of 4 h. Following the synthesis, characterizations of the synthesized products are conducted by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and scanning electron microscope (SEM). From the results of the experiments, three types of lanthanum borates of; LaBO6, LaBO3 and La(BO2)3 were observed at different reaction parameters. Among these three types of lanthanum borates LaBO3 phase were obtained as a major phase.

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