KATI-HAL YÖNTEMİ İLE DÜŞÜK SICAKLIKLARDA LABO3 ÜRETİMİ VE KARAKTERİZASYONU

Öz

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.

Anahtar Kelimeler

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

Low Temperature Solid-State Synthesis and Characterization of LaBO3

Öz

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.

Anahtar Kelimeler

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

Kaynakça

1. Badan, C. (2012) Microwave assisted synthesis of rare earth ions doped lanthanum orthoborate, their characterizations and ınvestigations of luminescence properties, The Graduate School of Natural and Applied Sciences, M. Sc. Thesis, Middle East Technical University, Ankara.
2. Doi, Y., Satou, T. and Hinatsu, Y. (2013) Crystal structures and magnetic properties of lanthanide containing borates LnM(BO3)2 (Ln=Y, Ho–Lu; M=Sc, Cr), Journal of Solid State Chemistry, 206, 151-157. doi: 10.1016/j.jssc.2013.08.015
3. Harben, P. W., Kužvart, M. (1996) Industrial minerals: a global geology. Industrial Minerals Information Ltd, London.
4. Hu, Z. S., Dong, J. X., Chen, G. X. and He, J. Z. (2000) Preparation and tribological properties of nanoparticle lanthanum borate, Wear, 243, 43-47. doi: 10.1016/S0043-1648(00)00415-4
5. Jun, L., Shiyang, G., Shuping, X., Bing, L. and Rongzu, H. (1997) Thermochemistry of Hydrated Magnesium Borates, The Journal of Chemical Thermodynamics, 29, 491-497.
6. Kıpçak, A. S. (2013), Çeşitli Magnezyum ve bor kaynaklarından farklı yöntemler ile yapay magnezyum borat üretimi ve üretim parametrelrinin ı̇ncelemesi, Doktora Tezi, Yıldız Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul.
7. Kipcak, A. S., Moroydor Derun, E. and Piskin S. (2014) Synthesis and characterization of magnesium borate minerals of admontite and mcallisterite obtained via ultrasonic mixing of magnesium oxide and various sources of boron: a novel method, Turkish Journal of Chemistry, 38, 792-805. doi: 10.3906/kim-1307-61
8. Kipcak, A. S., Yildirim, M., Aydin Yuksel, S., Moroydor Derun, E. and Piskin S. (2014) The synthesis and physical properties of magnesium borate mineral of admontite synthesized from sodium borates, Advances in Materials Science and Engineering, 2014, ID 819745. doi: 10.1155/2014/819745

9. Lemanceau S., Bertrand-Chadeyron, G., Mahiou, R., El-Ghozzi, M., Cousseins, J. C. and Conflant, P. (1999) Synthesis and Characterization of H-LnBO3 Orthoborates (Ln:La, Nd, Sm, and Eu), Journal of Solid State Chemistry, 148(2), 229-235. doi: 10.1006/jssc.1999.8437
10. Lin, J., Sheptyakov, D., Wang, Y. and Allenspach, P. (2004) Structures and phase transition of vaterite-type rare earth orthoborates: a neutron diffraction study, Chemistry of Materials, 16, 2418-2424. doi: 10.1021/cm0499388
11. Ma, J., Wu, Q. (2007) Assembly and deagglomeration of lanthanum orthoborate nanobundles, Journal of the American Ceramic Society, 90(12), 3890-3895. doi: 10.1111/j.1551-2916.2007.02071.x
12. Moroydor Derun, E., Kipcak, A.S., Senberber, F. T. and Sari Yilmaz, M. (2015) Characterization and thermal dehydration kinetics of admontite mineral hydrothermally synthesized from magnesium oxide and boric acid precursor, Research on Chemical Intermediates, 41,853–866. doi: 10.1007/s11164-013-1237-6
13. Rajaramakrishna, R., Karuthedath, S., Anavekar, R. V. and Jain, M. (2012) Nonlinear optical studies of lead lanthanum borate glass doped with Au nanoparticles, Journal of Non-Crystalline Solids, 358(14), 1667-1672. doi: 10.1016/j.jnoncrysol.2012.04.031
14. Shmyt’ko, I. M., Kiryakin, I. N. and Strukova, G. K. (2013) Features of LaBO3 phase formation during solid phase synthesis from the amorphous precursor state, Physics of the Solid State, 55(7), 1468-1475. doi: 10.1134/S1063783413070305
15. T. R. Prime Ministry SPO (2006) Boron Operations Group report: Ninth development plan (2007–2013), Chemical Industry Private Expertise Commission.
16. Woods, W. G. (1994) An Introduction to Boron: History, Sources, Uses and Chemistry, Office of Environmental Health and Safety, Environ Health Perspect,102 (Suppl 7), 5-11.
17. Yongzhong, J., Shiyang, G. Shuping, X. and Jun, L. (2000) FT-IR spectroscopy of supersaturated aqueous solutions of magnesium borate, Spectrochimica Acta Part A, 56, 1291–1297. doi: 10.1016/S1386-1425(99)00227-9