KATI-HAL YÖNTEMİ İLE DÜŞÜK SICAKLIKLARDA LABO3 ÜRETİMİ VE KARAKTERİZASYONU

Abstract

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, katı-hal 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:H₃BO₃ olarak 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.

Keywords

• lantanit,boratlar; lantan boratlar; katı-hal; XRD; SEM

Low Temperature Solid-State Synthesis and Characterization of LaBO3

Abstract

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 and 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 (La₂O₃) 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 solid-state 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; La₃BO₆, 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.

Keywords

• lanthanide,borates; lanthanum borates; solid-state; XRD; SEM

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